Chapter 5: Changes in the water cycle

Chapter description

This chapter assesses past and future climate-related changes in components of the water cycle that impact freshwater availability in Canada, namely, the atmospheric component of the water cycle (evaporation and precipitation), streamflow, surface water storage (lakes and wetlands), groundwater, droughts, and floods.

Chapter key messages

Plain language summary^{Footnote 1}

The water cycle involves the movement of liquid, solid, and gaseous forms of water among reservoirs in the ocean, atmosphere, land surface and subsurface, and cryosphere. Many components of this cycle govern freshwater availability in Canada. In this chapter, freshwater availability is defined as water at the surface (streams, lakes, and wetlands), in the soil, and in aquifers (groundwater) that is available for both human and ecosystem use. We use multiple lines of evidence to assess past and future changes in components of the water cycle that are important to freshwater availability in Canada. The assessment in this chapter complements material in chapters 2 and 3 on past and future changes to temperature and precipitation, in Chapter 4 on large-scale circulation variability, in Chapter 6 on changes to the cryosphere, and in Chapter 8 on changes to extremes.

Past and future changes in the atmospheric component of the water cycle are associated with increased total annual precipitation and heavy precipitation events and, to a lesser extent, increased warm-season evaporation. Climate warming is also impacting the precipitation phase, with changes in the proportion of rainfall versus snowfall. These changes are altering the traditional water balance in many regions across the country and are projected to continue doing so.

Since the first edition of Canada’s Changing Climate Report and its assessment of freshwater availability (Bonsal et al., 2019), the observed changes in the seasonal characteristics of streamflow have included even earlier spring freshets (higher flows resulting from snow and ice melt in spring), higher winter flows, and, for many regions, lower summer flows. These changes are altering the nature of streams from nival (snowmelt-dominated) flow regimes to pluvial (rainfall-dominated) or mixed flow regimes. These changes are consistent with observed warming and related changes in snow, ice, and the precipitation phase. Annual streamflow magnitudes have increased in regions of northern Canada dominated by permafrost. This increase is due to increases in precipitation, and to permafrost thawing, which makes it possible for this precipitation water to infiltrate deeper, thus increasing streamflow. In other parts of the country, annual streamflow magnitudes, as well as surface water levels (meaning the amount of water stored in lakes and wetlands) and shallow groundwater aquifers, have for the most part been variable over time, with no clear trends. The variability in surface water levels has, in some cases recently, been marked by rapid transitions from extreme-low to extreme-high levels and vice versa. The occurrence of hydroclimatic extremes, namely droughts and floods, has been variable over time, with no clear trends during the last 50 to 100 years.

Continued warming and associated changes in precipitation (Chapter 3), shorter durations of snow cover, shrinking mountain glaciers, and increased permafrost thaw (Chapter 6) are, as described above, expected to continue to drive changes in the seasonal characteristics of streamflow. Annual streamflow is projected to increase in some areas (mainly northern regions dominated by permafrost) and remain constant in others. Future surface water levels may fall in some regions and rise in others because of the many complex factors that affect surface water storage. These factors include duration of ice cover, amount of open-water evaporation, temporal distribution of increased precipitation, and permafrost thaw and associated lake drainage or in some cases lake expansion. All these factors are being influenced by a warming climate.

Owing to the limited amount of data and the complexity of groundwater systems, assessing future changes in Canada’s groundwater systems due to climate change is difficult. Groundwater recharge in spring is projected to occur earlier in the year because of earlier snowmelt and winter rain events. In addition, the biggest groundwater changes will continue to be in northern landscapes that are impacted by thawing permafrost. Given its slower response time to climate as compared to surface freshwater, groundwater is expected to remain one of the freshwater resources that is less impacted by a changing climate for the next several decades.

Future increases in the frequency and intensity of meteorological droughts (decreased precipitation and increased evaporation) and agricultural droughts (decreased soil moisture) are anticipated, especially during summer across central and southern Canada, with the greatest changes in the Prairies. Summer hydrological droughts (lower surface water levels) are also projected to increase in many southern regions of Canada, mainly because of increased evaporation and lower runoff from mountainous areas. These changes are expected to be more prominent under higher warming levels, which tend to occur later in the century under a range of emission scenarios.

Changes in the frequency and intensity of streamflow-driven flooding are dependent on various factors. Future increases in extreme precipitation are expected to increase the potential for future flash flooding, including in urban areas. Warming temperatures are also projected to cause earlier floods driven by snowmelt, ice jams, and rain on snow. However, it is not clear how projected higher spring temperatures and reduced snow cover will combine to affect the frequency and magnitude of future flooding driven by snowmelt and ice jams.

The assessment of the water cycle outlined above is entirely consistent with the assessment in the first edition of Canada’s Changing Climate Report (Bonsal et al., 2019), with the overall weight of the evidence in this report being even stronger for streamflow and hydroclimatic extremes (droughts and floods). However, uncertainty about future changes in surface water levels and groundwater remains because of the complexity of these systems. Changes in freshwater availability are expected to be greater toward the end of this century under higher warming levels, given the greater associated climate changes. Of particular concern are potential declines in freshwater availability in regions that currently rely on snowmelt and ice melt as freshwater sources, as well as regions where permafrost thaw is changing streamflow amounts and surface water levels. However, both the timing and amount of freshwater in all regions of Canada are expected to be affected in some way. It is also anticipated that the altered water cycle will lead to more frequent and more severe water-related extremes (droughts and floods) and subsequent water shortages and excessive surpluses. These extremes will require adaptive measures and integrated water management approaches to ensure water security and resilience in the face of a changing climate.

5.1: Introduction

Freshwater is essential to all life. In Canada, adequate freshwater supplies are fundamental to the environment and many social and economic activities, including industry, electricity generation, recreation, and First Nations, Inuit and Métis ways of life. They are also crucial to food security and the provision of drinking water. Canada has an abundance of freshwater in the form of lakes, rivers, wetlands, aquifers (bodies of rock or sediment that hold groundwater reserves in liquid or frozen form), water stored in snowpacks (snow that accumulates and compresses over a season before melting), and glaciers, as well as in the soil. In fact, Canadian lakes, rivers, and wetlands hold around 20% of the world’s surface freshwater. Canada is home to more than 8,500 rivers and more than 875,000 lakes with a surface area greater than 0.1 km², covering almost 9% of the country (Federal, Provincial and Territorial Governments of Canada, 2010; Messager et al., 2021), while wetlands cover an estimated 13% (1.29 million km²) of the country . Canada also has reserves of an estimated 70,000 km³ of groundwater in the 200 m immediately below the surface (Rivera, 2014).

Freshwater availability is primarily governed by many complex processes and interactions in the water cycle (a simplified version is provided in Figure 5.1). During this cycle, water continuously moves through its liquid, solid, and gaseous forms among reservoirs in the ocean, atmosphere, biosphere, land surface, subsurface, and cryosphere (various forms of ice) (e.g., IPCC, 2014). Some of the water that evaporates from oceans and the land surface falls on land as precipitation, which provides soil moisture and streamflow and recharges groundwater. A portion may also accumulate on the surface as snow, which also provides soil moisture and streamflow and recharges groundwater after it melts. Precipitation and snowmelt either supply bodies of surface water and eventually evaporate, or infiltrate into the soil and are subsequently taken up by vegetation and transpired back to the atmosphere. Soil water can flow rapidly to streams and lakes through highly permeable subsoils or percolate down to recharge deeper groundwater aquifers. This deeper water flows to streams, bodies of surface freshwater, and the ocean much more slowly, over periods ranging from days to thousands of years, depending on the permeability of the geologic formations. Human water management, including dams, reservoirs, and water withdrawals, as well as land use changes, such as urbanization, also have a major impact on the water cycle. These disturbances by humans often make it difficult to discern when climate-related change is affecting freshwater.

Figure take-away: The water cycle includes many components, and complex processes and interactions that affect freshwater availability in Canada.

Figure 5.1: Diagram of the water cycle. Water that evaporates from oceans is transported over land, where it falls as precipitation. It then moves back to the atmosphere through evapotranspiration from soils, plants, and surface water, or is stored as ice and snow, or makes its way to rivers, lakes, and groundwater (via various pathways), where it eventually flows back to the ocean. Adapted from: Bonsal et al. (2019).

The water cycle includes many hydroclimatic processes (interactions between the Earth’s climate and the water cycle encompassing the movement and distribution of water)—some in the atmosphere, some on the land’s surface, and some below the land’s surface. This chapter focuses only on the components of the water cycle that directly affect freshwater availability across Canada. Given the cross-cutting nature of the water cycle, some processes are assessed in other chapters of this report (Figure 5.2). Section 5.2 of this chapter focuses on changes in the atmospheric component of the water cycle, including evaporation and precipitation. Sections 5.3, 5.4, and 5.5 assess changes in freshwater availability with respect to the surface and subsurface storage components of the water cycle, including the amount and timing of streamflow (5.3), lakes and wetlands (5.4), and groundwater (5.5). Hydroclimatic extremes related to the water cycle, including droughts and floods, are assessed in sections 5.6 and 5.7, respectively. Section 5.8 then provides an overview of key knowledge gaps and emerging issues, while section 5.9 gives the chapter’s integrated assessment of changes in the water cycle.

Our assessment is primarily based on information regarding bodies of water compiled by federal, provincial, and territorial monitoring networks. However, the density of their observation points for the freshwater availability indicators (such as streamflow, lake levels, soil moisture, and groundwater) varies across the country, with monitoring at many closely located points in some areas, but no monitoring in others, especially in much of northern Canada. Measurements from remote sensing, gathered by satellites, provide continental freshwater indicators that can, in some instances, be used to assess past changes over the last approximately 30 to 40 years. The data from both sources—monitoring networks and remote sensing—are used in this chapter to assess past changes in surface water and freshwater across the country.

Future changes in the atmospheric component of the water cycle are primarily determined using output from global climate models (GCMs) and regional climate models (RCMs) for different greenhouse gas emissions scenarios or future global warming levels. Future changes in surface and subsurface freshwater availability are mostly determined using hydrological models, which incorporate temperature and precipitation output from those climate models. For some freshwater variables, such as runoff and soil moisture, direct output from climate models is available and can be used to assess future changes. Our assessment includes studies based on modelling results from the most current GCMs, the Coupled Model Intercomparison Project Phase 6 (CMIP6) GCMs, which use emissions scenarios based on shared socio-economic pathways (SSPs) (for the CMIP6 results, see Chapter 3, section 3.3.1). However, our assessment also includes some studies based on earlier modelling results from the Coupled Model Intercomparison Project Phase 5 (CMIP5) GCMs, which used emissions scenarios based on representative concentration pathways (RCPs). Studies that compared hydrological indicators between CMIP5 and CMIP6 projections were consistently in agreement for many regions of Canada, with lower uncertainty in general among CMIP6 models (Martel et al., 2022). Note that much of the water cycle–related literature tends to focus on higher emissions scenarios, representing higher global warming levels.

This assessment is based on national, regional, and relevant global studies, along with information on changes in annual and seasonal average temperature and precipitation from chapters 2 and 3, changes in the cryosphere from Chapter 6, and changes in extremes from Chapter 8. It also mainly focuses on new information that has emerged since the corresponding assessment of changes in freshwater availability in the first edition of Canada’s Changing Climate Report (Bonsal et al., 2019).

Figure take-away: A visual snapshot of the contents of this chapter and of important cross-chapter linkages.

Figure 5.2: Visual guide to Chapter 5 content and cross-chapter linkages.

5.2: Atmospheric component of the water cycle

Key message 5.1: The atmospheric component of Canada’s water cycle has been altered and will continue to be altered by human influence (medium confidence).^{Footnote 2} Total annual precipitation has increased and is projected to continue to increase (high confidence). While there is only low to medium confidence in observed increases in the frequency and intensity of different types of heavy precipitation, there is high confidence these will increase in the future. Warm-season evaporation has increased and is projected to continue to increase across much of Canada, including over open water because of longer ice-free periods (low confidence). The 0°C air temperature isotherm (constant temperature line) is projected to move farther north and to higher elevations across Canada (medium confidence), which is expected to result in changes in the proportion of rainfall versus snowfall.

The atmospheric component of the water cycle primarily consists of evaporation from bodies of surface water to the atmosphere, evaporation from the surface land and vegetation to the atmosphere (evapotranspiration; ET), the movement of the water vapour in the atmosphere, and precipitation back to the surface (Figure 5.1) (e.g., Oki & Kanae, 2006). Rising temperatures lead to increases in both evaporative demand and the atmosphere’s water-holding capacity, which in turn leads to higher levels of atmospheric water vapour (Held & Soden, 2006; Trenberth et al., 2003). This higher amount of atmospheric water vapour increases the potential for water vapour to condense into clouds and for precipitation to occur. A warming climate also increases water vapour transport into weather systems, which leads to an intensification of precipitation on various timescales, ranging from sub-daily to seasonal (Allan & Soden, 2008; Trenberth, 2011). This intensification of precipitation exacerbates the severity of some flood-related hazards (Bonsal et al., 2019). As global temperatures rise, both exceptionally wet and dry events may become more severe (Diffenbaugh et al., 2017; Dwyer & O’Gorman, 2017). However, changes in atmospheric circulation patterns (Chapter 4) influence where and how often these extreme periods occur, resulting in significant regional variations and seasonal disparities (Allan et al., 2020; Pfahl et al., 2017; Shepherd, 2014).

Considerable work has been done on the atmospheric component of the global water cycle, and it is generally concluded that global warming has contributed to an overall increase in ET, atmospheric water vapour, and precipitation intensity, and will continue to do so (Douville et al., 2021; IPCC, 2021). Based on an understanding of global-scale changes, this section assesses past and future changes related to atmospheric water as they affect freshwater availability in Canada. These changes include shifts in open-water evaporation, ET, potential evapotranspiration (PET), and precipitation amount, phase, and intensity.

5.2.1: Past changes

5.2.1.1: Evaporation

Open-water evaporation and ET have been influenced by past climate-related changes. Earlier onset of spring has generally increased ET amounts because, as surfaces become snow-free, bodies of water lose ice cover sooner and vegetation begins transpiring earlier (DeBeer et al., 2021). Similarly, later freezing conditions in fall have extended the ET period. Although warmer air temperatures, longer snow- and ice-free periods, and increased water-holding capacity of the atmosphere all have the potential to increase open-water evaporation (Blanken et al., 2000; Spence et al., 2018), long-term trends are challenging to detect because of the difficulty in measuring open-water evaporation. There have been no large-scale systematic trend analyses for measured lake evaporation for Canada as a whole, but measurements for some regions, using various approaches and covering different time periods have provided some insights into annual evaporation rates (Gibson et al., 2019, 2020; Spence & Hedstrom, 2018). The general pattern from these measurements suggests increasing rates of evaporation into the atmosphere, but determining whether trends are significant has been difficult because of high year-to-year variability and a lack of long-term measurements (Gronewold & Stow, 2014).

Wind speed also significantly influences evaporation by removing water vapour from surfaces, thus allowing more evaporation to occur. Across Canada, past trends in wind speed have been variable, mainly decreasing from the southern Prairies to central Quebec and increasing in British Columbia and northern regions (Chapter 2, section 2.6). These variable trends also highlight the difficulty in assessing past changes in evaporation, underscoring the need for further research on the wind’s role in evaporation changes in Canada.

As alluded to above, the duration of ice cover plays a key role in determining the length of the open-water season (the period during which a lake is ice-free), thereby influencing the amount of water loss from lakes through evaporation. A recent global study on lakes using satellite observations and modelling tools quantified the rates of evaporation for 1985 to 2018 (Zhao et al., 2022). The simulations from this study for Canada indicate that the annual rates of lake evaporation increased over much of the northern, central, and eastern parts of the country (Figure 5.3).

Trends in ET for Canada are, like those in open-water evaporation, difficult to assess because of the lack of large-scale systematic trend analyses. Local and regional studies have been conducted across various parts of the country using many approaches and covering different time periods (Armstrong et al., 2015; Burn & Hesch, 2007; Li et al., 2020; Shah et al., 2022; Spence et al., 2024). In cold high-latitude regions, where temperature is the main factor limiting evaporation, increases in ET are often observed as temperatures rise. While in dry regions, where water availability is the factor limiting evaporation, ET has remained stable. Over recent decades, ET has increased in the Prairie and boreal forest regions of the country. These changes are linked to rising temperatures and the increased capacity of the warmer atmosphere to hold moisture. Furthermore, the Arctic and sub-Arctic areas of Canada are also experiencing a rapid increase in ET due to plant growth (vegetation greening) and rising temperatures (Zeng et al., 2018), which have been linked to anthropogenic (human-caused) climate warming.

The general upward trends in simulated lake evaporation (Figure 5.3) are mostly consistent with a Canada-wide assessment of long-term trends in PET (which is a measure of atmospheric water demand) and were primarily driven by rising temperatures (Li et al., 2020). This pattern of increasing PET extends beyond Canada to the global scale and is partly attributed to anthropogenic forcing (IPCC, 2021).

Figure take-away: Simulations indicate lake evaporation across much of Canada has increased historically.

Figure 5.3: Map of trends in simulated evaporation rates in mm/yr from lakes across Canada for the period 1985 to 2018. The Canadian data were obtained from global information presented in Zhao et al. (2022). Red colours denote increasing evaporation rates, whereas blue colours denote decreasing rates. Significance is assessed at the 5% level (meaning there is ≤ a 5% chance of concluding that an effect or trend exists when it does not).

5.2.1.2: Precipitation

Total annual precipitation has increased across Canada, with the largest percentage increases during winter and spring (Chapter 2, section 2.5). Heavy precipitation events have also increased (Chapter 8, section 8.3). These findings are consistent with several North American and global studies.

The precipitation phase has also been changing across Canada, with more precipitation falling as rain than snow (Chapter 2, section 2.5). This increase in rain versus snow has affected hydrological regimes through changes to the magnitude and timing of snow accumulation and snowmelt, a higher number of rain-on-snow (ROS) events, and a shift from nival (snowmelt-dominated) to pluvial (rainfall-dominated) streamflow regimes (section 5.3) (DeBeer et al., 2021).

The precipitation type (rain, freezing rain, or wet snow) is largely driven by the occurrence and location of near 0°C (-2 to 2°C) surface air temperatures and the vertical temperature and humidity structure (e.g., Stewart et al., 2015). Precipitation can alter the snowpack characteristics and the timing of the snowmelt season. No trend in the occurrence of near 0°C conditions has been identified over the last several decades at most stations across Canada (Mekis et al., 2020). For example, near 0^oC occurrences remained unchanged from 1956 to 2020 at Terrace, British Columbia, even though average air temperature has increased (Cardinal et al., 2024). On large scales, Bonsal and Prowse (2003) assessed 20th-century trends and variability for 0°C dates during spring and fall in Canada and found significant trends toward earlier springs (particularly in western areas) but little change during fall.

5.2.2: Future changes

5.2.2.1: Evaporation

With continued warming, it is expected that open-water evaporation and ET will increase across Canada. However, only a few regional studies on future open-water evaporation and ET have been conducted. For example, using a very high emissions scenario (RCP8.5), future increases in ET were projected across the Mackenzie and Saskatchewan river basins during the warm season because of increasing atmospheric evaporative demand (PET) (Kurkute et al., 2020). More studies have examined future changes in PET, mainly using various drought indices (precipitation minus PET), with the majority revealing projected increases in PET over many parts of the country. These increases lead to more occurrences of meteorological and agricultural droughts (section 5.6) (Zare et al., 2023).

A key area of uncertainty in projecting future ET and PET rates, however, relates to vegetation responses associated with climate change. These responses often involve various physiological adaptations, which in turn influence transpiration rates. Complex land-atmosphere feedbacks associated with changes in vegetation cover and soil moisture can further add to this uncertainty (IPCC, 2022a). These vegetation-related uncertainties are particularly relevant in Canada’s boreal and Arctic regions, where rapid warming is driving substantial ecological changes (Reich et al., 2022).

5.2.2.2: Precipitation

Total precipitation across Canada is projected to continue to increase, particularly during winter and spring (Chapter 3, section 3.5). In addition, more heavy precipitation events are projected to occur across most of North America, including Canada (Chapter 8, section 8.3) (Li et al., 2021, 2025; Li et al., 2019; Rasmussen et al., 2017) , which could lead to the water cycle changes (Scaff et al., 2020). Less-frequent but more-intense precipitation events can result in more runoff. They can also lead to drier conditions between occurrences of precipitation because the soil has difficulty absorbing water when intense rainfall occurs (Box 5.1).

With climate warming, a substantial shift in snow regime and the proportion of snowfall versus rainfall is expected (DeBeer et al., 2021; López-Moreno et al., 2020). Transitions from snow to rain are also anticipated to occur at more northern latitudes and at higher elevations, depending to some extent on the season and on the geographic position of a given area on the landscape (such as altitude and slope orientation) relative to prevailing winds (Almonte & Stewart, 2019; Thériault et al., 2023). In many parts of Canada, an increase in the frequency of ROS events and in the magnitude of mid-winter melt events is projected, except where snowpacks are marginal, in which case there will be fewer ROS events given the loss of snow cover (e.g., López-Moreno et al., 2020). In relatively warmer regions, ROS events are projected to decrease because of reduced snowpacks and the shorter duration of snow cover on the ground, which impact runoff (DeBeer et al., 2021). These temperature and precipitation phase changes will also have implications for the cryosphere (including snow, glaciers, lake and river ice, permafrost, and seasonally frozen soils), as discussed in Chapter 6, and for hydrological regimes and runoff timing, as discussed in section 5.3. They will also impact extreme events such as ROS or rain-on-ice flooding, and flooding associated with extreme snow- and ice-melting events (section 5.7).

Changes in the precipitation phase occur when the air temperature is near 0°C. The location of the 0°C air temperature isotherm, compared to its location from 1976 to 2005, is projected to move northward in Canada over the remainder of the 21st century (Figure 5.4) (Stewart et al., 2019). Regional variations are apparent and can be attributed to topography and large bodies of water such as Hudson Bay. This change in the location of the 0°C isotherm will directly affect the precipitation phase and timing of snowmelt and spring freshets, which will in turn affect the water cycle and resulting freshwater availability in Canada.

Figure take-away: There is a northward shift in the location of the 0°C air temperature isotherm during spring and fall with higher amounts of global warming.

Figure 5.4: Maps of the average location of the 0°C air temperature isotherm during a) March and b) November from 1976 to 2095. The CMIP5 multi-model ensemble and a very high emissions scenario (RCP8.5) were used. The colours represent different future periods, and the grey shading is the region bounded by the 25th and 75th ensemble average air temperature percentiles (p25–p75) from 2086 to 2095. Source: Stewart et al. (2019).

Finally, warmer air generated by global warming increases the amount of water vapour in the atmosphere, which leads to an increase of the global average for water vapour residence time, meaning that water vapour is staying in the atmosphere longer before falling as precipitation. Estimates suggest a 3 to 6% increase per degree Celsius of warming (Gimeno et al., 2021). Water vapour staying in the atmosphere longer can lead to its transport over a longer distance. Depending on the atmospheric conditions, this change in moisture transport can trigger precipitation at different locations, leading to a change in spatial and temporal precipitation patterns. These changes in precipitation patterns will be particularly marked in mid-to-high-latitude regions like Canada where temperature increases are projected to be greater than the global average (Chapter 3, section 3.4). As assessed in this chapter and in chapters 2, 3, and 8, the combined effects of changes in precipitation patterns, snow-to-rain transitions, and increased evaporation will substantially impact Canada’s water resources, ecosystems, and agriculture.

Box 5.1: Understanding hydroclimatic swings and their effects on drought and flood risk in Canada

The dynamic interplay between floods and droughts, particularly in a warming climate, is becoming more pronounced. Climate change is altering the hydrological cycle, leading to more frequent and severe hydroclimatic extremes. These events can occur in rapid succession, compounding the risks for ecosystems, infrastructure, and communities. These rapid transitions between dry and wet conditions are often referred to as hydroclimatic swings or weather whiplash. Research on hydroclimatic swings provides insight into the growing challenge of managing these extreme events, as they are projected to increase in frequency and intensity under future climate scenarios (Na & Najafi, 2024; RahimiMovaghar et al., 2025; Rezvani, Na, et al., 2023; Rezvani, RahimiMovaghar, et al., 2023). The mechanisms driving these transitions are multifaceted. Shifts in atmospheric circulation patterns (Chapter 4), including the frequency of atmospheric rivers and the jet stream (a fast-flowing, narrow band of wind in the upper atmosphere that influences weather patterns), can play an important role in driving the rapid transitions between extremes, such as droughts and floods (Na & Najafi, 2024). Similarly, heatwaves and prolonged dry spells can harden soils, reducing their ability to absorb water. This condition increases the likelihood of flooding if an intense precipitation event follows a drought (RahimiMovaghar et al., 2024).

Recent events in Canada highlight the reality of these transitions. In 2021, British Columbia experienced extreme heatwaves in late June and early July, followed by widespread wildfires through the summer months. These events were succeeded by back-to-back atmospheric river events in November, which caused severe flooding and landslides, resulting in significant infrastructure damage and displacement across southern British Columbia (Gillett et al., 2022). The Canadian Prairies are also increasingly vulnerable to such transitions, with dry-to-wet extremes often occurring within short time frames (Wheaton et al., 2023). In 2021, a drought affected nearly all (99%) of the agricultural regions in the Prairies. The drought was followed by heavy rainfall, which caused localized flooding and significant damage to infrastructure. Projections for northwestern North America indicate an increased frequency of lagged compound flood and drought events, with transition times decreasing under higher global warming scenarios (Na & Najafi, 2024).

5.2.3: Confidence terms in key messages: summary of evidence

Key message 5.1: The atmospheric component of Canada’s water cycle has been altered and will continue to be altered by human influence (medium confidence). Total annual precipitation has increased and is projected to continue to increase (high confidence). While there is only low to medium confidence in observed increases in the frequency and intensity of different types of heavy precipitation, there is high confidence these will increase in the future. Warm-season evaporation has increased and is projected to continue to increase across much of Canada, including over open water because of longer ice-free periods (low confidence). The 0°C air temperature isotherm (constant temperature line) is projected to move farther north and to higher elevations across Canada (medium confidence), which is expected to result in changes in the proportion of rainfall versus snowfall.

We have medium confidence in the first statement regarding the altered atmospheric component of Canada’s water cycle, based on the assessment of each of these atmospheric components in the subsequent three statements, as well as the consistency with several North American and global studies. We have high confidence in the assessment of past and future precipitation (annual total and heavy events), given the consistency in results for Canada as a whole (chapters 2, 3, and 8). However, some regional variability is apparent, particularly with heavy events (Chapter 8, section 8.3). Our low confidence in past and future increases in warm-season evaporation across much of Canada is due to the lack of nationwide studies in past and future open-water evaporation and ET, along with the difficulties in measuring and modelling evaporation and ET. Although many studies project increases in PET, there are uncertainties due to future vegetation responses associated with climate change. Confidence in greater future evaporation is increased by the consistency of projected warming and the resulting increase in open-water evaporation and ET due to longer ice and snow-free periods. We have medium confidence in the future movement of the 0°C air temperature isotherm farther north and to higher elevations. This assessment is based on a direct Canada-wide study on future 0°C air temperature isotherms (Figure 5.4) and the projection of future warming in Chapter 3. This shift is expected to result in changes in the proportion of rainfall versus snowfall; however, no studies have been carried out on this topic. No statement is made on past changes of the 0°C air temperature isotherm, given the lack of evidence.

5.3: Streamflow magnitude and timing

Key message 5.2: The greatest changes in streamflow magnitude across Canada have occurred and are projected to continue to occur on a seasonal basis. During the last 50 to 70 years, streamflow amounts have increased in winter and spring, and in some areas have decreased during summer (high confidence). Winter increases are projected to continue across the entire country, while summer decreases are projected across western Canada (high confidence).

Key message 5.3: Annual streamflow amounts have increased in regions of northern Canada dominated by permafrost and will continue to do so (high confidence). No long-term historical or projected changes in annual streamflow are evident across the rest of the country (high confidence).

Key message 5.4: The timing of spring peak streamflow has shifted across Canada to earlier in the season because of the earlier onset of spring freshets. This shift has resulted in changes from more snowmelt-dominated streamflow regimes to rainfall-dominated regimes. These changes are projected to continue (high confidence).

Canada has more than 8500 rivers and streams of various lengths, which have a total drainage area equivalent to 6% of the global land area (Federal, Provincial and Territorial Governments of Canada, 2010). Canadian rivers support socio-economic activities, such as water supply, agriculture, recreation, and hydropower production (Zaerpour et al., 2021). Natural climate variability has influenced water availability throughout Canada and will continue to do so. Human-caused climate change is also a factor that alters the amount, timing, and distribution of streamflow, with implications on dam operation, flood control, and other water resource management activities (Koshida et al., 2015). Studies that assess past trends in streamflow in Canada have analyzed past streamflow variables on watershed, regional, and national scales. However, these studies have a limited ability to provide perspectives Canada-wide, in large part because of great regional variations in climate and watershed characteristics. Future streamflow changes are assessed using climate output (precipitation and temperature) from various GCMs and RCMs that provide input to a hydrological model. The multitude of climate and hydrological models used in these studies adds uncertainty to projections about changes in streamflow (Seneviratne et al., 2012).

5.3.1: Past changes

5.3.1.1: Streamflow magnitude

Streamflow magnitude is a key indicator in assessing changes in surface water availability. It is assessed on daily, monthly, seasonal, and annual scales to determine changes in overall flow volumes and timing, and to examine changes in the flow regime. The first edition of Canada’s Changing Climate Report (CCCR2019) concluded that there had been no consistent trends in annual streamflow amounts for Canada as a whole (Bonsal et al., 2019). Since then, several regional studies have been undertaken, with many being in northern permafrost regions. For example, an analysis of streamflow across northern permafrost regions with varying degrees of permafrost occurrence shows significant increases in annual average streamflow for the period from 1976 to 2021 in most of these permafrost-dominant systems (Bennett et al., 2023). These streamflow increases are due to the fact that as the region experiences warmer and wetter conditions in a changing climate, permafrost thaws and active layers deepen, resulting in increased groundwater contribution to streams and a larger proportion of the water received at the surface as precipitation making its way into streams. Analysis of changes in streamflow from 1945 to 2018 at 84 hydrometric stations across the permafrost region of Canada found that 68% of stations showed increasing daily minimum flows (44% increasing at the 10% significance level, meaning there is ≤ a 10% chance of concluding that an effect or trend exists when it does not). Similarly, 62% had increasing daily average flows (15% increasing at the 10% significance level) (. Shrestha, Pesklevits, et al., 2021). Most of the stations in the permafrost region with increases in streamflow are in northwestern Canada, while there are no changes or decreases in streamflow in southern and eastern regions (Figure 5.5). Similarly, increases in average annual streamflow (18.1% rise relative to average annual streamflow) for the period from 1989 to 2013 were reported for 42 rivers across northern Canada (Déry et al., 2016), while a study of 49 North American rivers for the period from 1975 to 2015 revealed a generally upward trend in freshwater flow to the Arctic Ocean (Durocher et al., 2019). In summary, these studies indicate that streamflow in recent years has increased across much of Canada’s northern permafrost region, with most of the changes occurring in the western areas and during the winter and early spring seasons.

Figure take-away: Increases in annual streamflow in the permafrost region of Canada have been most evident in the northwest.

Figure 5.5: Maps of past trends in annual streamflow variables for the permafrost region of Canada from 1945 to 2018. a) Average flow, b) Minimum flow, c) Maximum flow, and d) Timing of maximum flow. Upward and downward trends at the 10% significance level (meaning there is ≤ a 10% chance of concluding that an effect or trend exists when it does not) are indicated by blue plus (+) and red minus (-) signs. Adapted from: Shrestha, Pesklevits, et al. (2021).

Several studies focusing on specific watersheds across Canada have shown both increasing and decreasing seasonal and annual changes in streamflow over the past few decades. Investigation of 113 Water Survey of Canada hydrometric stations having a record length of at least 75 years found no significant trend in annual streamflow at 92 stations, with significant increases at 17 and significant decreases at 4 stations scattered across the country (Hulley et al., 2019). Seasonally, there was a clear pattern of increasing flows across the north during the winter months. In central and southern Canada, many streams and rivers in the North Saskatchewan, Peace, and Athabasca river basins exhibited significant declining flows during summer and fall (DeBeer et al., 2016). While winter flow in the upper Athabasca River Basin has been slowly and steadily increasing since 1956 because of rising temperatures and the melting of snowpacks and glaciers, the warm-season flows in the middle and lower subregions declined up to 1981, then started to trend upward, with a rapid increase since 2015 (Zaghloul et al., 2022).

Monthly baseflow trends across Canada from 1989 to 2019 also showed notable upward trends from October to April across most of southern Canada and downward trends from June to September in Alberta, British Columbia, and the southern Northwest Territories (Murray et al., 2023). Analysis of 21 major rivers in the Hudson Bay drainage basin for the period from 1964 to 2013 showed an overall upward trend in annual streamflow, which was most pronounced in fall and winter and was moderate during summer (Stadnyk et al., 2019). River flow trends in the Athabasca and Peace river watersheds from 1956 to 2020 showed that annual average flow decreased from 1956 to 1981 but has since increased (Zaghloul et al., 2022). The Elbow River, in Alberta, is associated with significant increases from 1979 to 2015 in both annual flow and annual maximum daily flow (Zhou et al., 2022). Analysis of average annual flows for the period from 1930 to 2019 in 17 watersheds in southern Quebec reveals an increase for 12 rivers, which was more pronounced on the north shore of the Saint Lawrence River than the south, where a downward trend was found in 5 rivers (Assani, 2022). Another study in the upper Harricana River, in western Quebec, indicated that from 1915 to 2020, average streamflow in August and September decreased by 21 to 27%, while it increased from February to April by 24 to 28%, with no significant trend in average annual streamflow (Nolin et al., 2023). In summary, these studies reveal that streamflow during the last several decades has generally increased in winter and spring across most of the country, and in some areas (mainly western Canada) it has decreased during summer.

5.3.1.2: Streamflow timing

Streamflow timing and related streamflow regimes are important indicators of freshwater availability since water users and aquatic ecosystems are accustomed to having adequate water supplies at certain times of the year. Climate has a significant influence on the timing of streamflow events, such as the spring freshet, when flow substantially increases because of snowmelt. Climate also has a significant influence on shorter-duration maximum and minimum flows during the year. Higher winter and spring temperatures have had the biggest influence on longer-term trends of streamflow timing (Shrestha, Pesklevits,  et al., 2021; Stewart et al., 2005). CCCR2019 determined that the spring high-flow season (at the onset of the freshet) in most Canadian watersheds is now earlier, particularly across western Canada (Bonsal et al., 2019). Little research has been carried out since then, except for a global study of changes in river flow seasonality using monthly average data for 1965 to 2024 (Wang et al., 2024). The study found that approximately 21% of long-term river gauging stations showed changes in seasonal flow distributions, including increased winter and decreased spring streamflow in northern high-latitude regions (above 50°N), a phenomenon directly linked to human-caused climate change.

Streamflow regime is influenced predominantly by the prevailing climate in the region (e.g., Moore et al., 2017). In Canada, streamflow regimes are classified as nival (snowmelt-dominated), glacial (glacier-dominated), pluvial (rainfall-dominated), or mixed (e.g., Bonsal et al., 2019). Several Canada-wide studies have found that changes are occurring in streamflow regimes, but the nature and extent of these changes depend on their location. For example, flood (high-flow) magnitudes have generally decreased in snowmelt-dominated watersheds and increased in rainfall-dominated watersheds (Burn & Whitfield, 2016). An analysis of 46 long-term stations (23 in Canada and 23 in the United States) for the 80-year period from 1938 to 2017 confirms the findings that climate warming has led to increasing rainfall and its associated influence on flood-producing or high-flow–producing mechanisms (Burn & Whitfield, 2023). While strongly nival watersheds show no changes, roughly 15% of the stations show significant shifts toward the pluvial end of the flood regime continuum.

A study of glacial rivers in western Canada from 1960 to 2006 determined earlier occurrences in maximum flow and decreased summer flows in most of the rivers (Déry et al., 2009). Although no recent studies have been directly carried out on past changes in glacial streamflow regimes, the rapid retreat of Canadian glaciers (Chapter 6, section 6.5) strongly suggests that glacier-augmented late-summer flow has been and will continue to be reduced. Shifts in streamflow regimes and resulting changes in when and how much water is available, have direct impacts on users of freshwater, including individual communities who rely on sustainable water supplies that are being affected by climate warming (Case Story 5.1).

Analyses of trends at 105 streamflow stations in Canada found that for the period from 1966 to 2010, changes in natural streamflow regimes varied among different regions, while the dominant regime had shifted in more than 80% of the streams. These shifts were caused by simultaneous changes in multiple streamflow characteristics, such as monthly and seasonal flow magnitudes and the magnitude and timing of annual high and low flows (Zaerpour et al., 2021). Analysis of changes in the flood regimes and dominant flood-generating processes at 27 natural watersheds across Canada and the northern United States for the period from 1916 to 2015 also showed an increased prevalence of high-flow responses to rainfall. For nival-regime stations, this resulted in a shift to a more mixed regime, and for mixed-regime stations, a shift toward a more pluvial regime (Burn & Whitfield, 2017, 2018). All these observed changes in flow regimes are consistent with a warming climate. For cold-region rivers characterized by the yearly occurrence of river-ice formation and breakup, annual maximum water levels can occur either during the open-water season or when the river is ice-covered (Beltaos & Prowse, 2001). Analysis of annual maximum water levels during the ice-influenced and open-water periods at selected sites in the Canadian River Ice Database, using the data from 1965 to 2015 (Canadian River Ice Database - Open Government Portal) shows that the proportion of stations where maximum water levels occurred during open-water season increased from 36 to 41%, while the proportion of stations where maximum water levels mostly occurred under the influence of ice decreased from 36 to 31%. The proportion of stations with mixed types remained the same at 28%. This indicates a slight shift in flood regimes from ice-influenced to open-water–influenced at some of the stations analyzed.

Case Story 5.1: Towards a sustainable water supply for Ausuiktuq (Grise Fiord), Nunavut

The authors of this case story include Jimmie Qaaqpik, an Inuit Knowledge holder, long-term community member of Ausuiktuq (Grise Fiord), Nunavut, and Adult Education Facilitator at Nunavut Arctic College. David Burgess and Brad Danielson work for Natural Resources Canada (Ottawa) and have visited Ausuiktuq each spring for many years to monitor the local glacier and learn about the community's water supply needs. David Burgess was the lead author of the case story, Jimmie Qaapik provided much of the source material and historical perspective, and Brad Danielson provided additional comments and reviews.

Recommended citation:

Burgess, D, Danielsen, B., & Qaapik, J. (2026). Towards a sustainable water supply for Ausuiktuq (Grise Fiord), Nunavut [Case Story 5.1]. In Canada’s Changing Climate Report 2026. (pp. xx–xx). Government of Canada. DOI for the chapter.

Situated on the south shore of Ellesmere Island (76.4°N, 82.9°W) in the Qikiqtaaluk Region, Nunavut, Ausuiktuq is Canada’s northern most community. The hamlet was moved to its current location in 1961 after a failed attempt at settling on the Lindstrom Peninsula (1953–1961), where vegetation, wildlife, and freshwater resources were sparce. Despite the existing amenities at the new hamlet location (Case Story 5.1 Figure 1), survival was still a challenge as the hunters needed to adapt to the unfamiliar hunting practices required to harvest marine food sources, such as whale, walrus, and seal (Audlaluk, 2020).

Case Story 5.1 Figure 1: Photo of the RCMP station, barracks, and supply store in 1959, prior to the establishment of Ausuiktuq in 1961 (left), and of the hamlet of Ausuiktuq in 2012, population of approximately 150 (right).

The community settled near the mouth of an intermittent stream, which provided a plentiful source of water (Ford, 2014) from snowmelt, rain, and meltwater from glacier ice in the catchment area (Case Story 5.1 Figure 2). However, by the late 1970s, ice worms were discovered in the stream, forcing the community to move the water source to the northeast corner of the hamlet (Case Story 5.1 Figure 2), where it is fed by snowmelt from the nearby mountain gullies. This water supply flows from the mountain gullies across colluvial sediments in permafrost to a reservoir excavated using bulldozer, payloader, and manual digging.

Case Story 5.1 Figure 2: Map of upstream catchment area for the intermittent stream that flows through Ausuiktuq. The mainstream channel extends 9 km into the catchment basin to drain an area of 32 km². From 1960 to 2023, glacier coverage in the catchment area decreased from 6.7 to 2.5 km². Given the near complete loss of its western arm over this period of time, contributions to streamflow from the culturally significant Ausuiktuq Glacier see Boyer and Howe (2024), Global Glacier Casualty List Begin Exploring Ausuiktuq Glacier are currently negligible. The background is a true colour image from the European Space Agency’s Sentinel-2_L2A sensor acquired on July 31, 2023.

Due in part to its small catchment area (< 1 km²) (Keung et al., 2022) the supply of potable water from the mountain gully source has in some years been insufficient to meet the hamlet’s water needs through to the following melt season. In response, the community augments its water supply by melting glacier ice that is chipped from icebergs stranded near the community (Case Story 5.1 Figure 3), and freshwater bergy-bits in the sea ice (Fiord, 2014). However, mining glacier ice for drinking water is labour-intensive, and access to stranded icebergs in any given year is uncertain. As the hamlet population continues to grow (particularly in the summer months), it seeks to develop a more reliable potable water system to meet the community’s current and future water needs.

Case Story 5.1 Figure 3: Photos of the collection of icebergs as a local source of potable water in Ausuiktuq. The water supply is augmented with ice from bergs that become stranded in the local bay. Heavy equipment is often used to “chip” ice from locally stranded bergs (left), after which they are transported to the hamlet water silo (middle), and inserted manually into the silo and melted to augment the community’s supply of potable water (right) (Keung et al., 2022).

A potential solution to the water supply issue that has been proposed for Ausuiktuq is to switch back to the intermittent stream that served as the original water supply (Case Story 5.1 Figure 2) from 1961 to the late 1970s (Keung et al., 2022). Estimates of snowmelt, rainfall, and glacier melt indicate that there would currently be sufficient outflow from this approximately 32-km² basin to fill two of the hamlet water silos (capacity of 3.4 million litres each) annually. While snowmelt and rainfall account for approximately 80% of the total annual stream discharge, melt from glaciers and ice patches remain important contributors to maintaining the flow of the intermittent stream throughout the late summer season, when contributions from snowmelt are largely depleted.

Projected warming for high northern latitudes will challenge efforts aimed at securing and maintaining a reliable water supply system for the hamlet of Ausuiktuq. For example:

1. Thawing of the permafrost, the top of which currently lies approximately 1 m beneath the ground surface, could result in water seepage and thus a decline in the amount of water available for capture and storage.
2. As the melting glaciers and remnant ice patches disappear over the coming decades, an important mid-to-late summer water supply will no longer be available, thereby shortening the already brief period over which melt-water is collected.
3. Increases in the frequency of extreme warming events as projected for this region (Walsh et al., 2020) are likely to heighten the probability of flooding and damage to the hamlet’s water resource infrastructure.

The health and well-being of the citizens of Ausuiktuq relies on a clean, reliable, and abundant supply of potable water. Ongoing efforts to develop such a system will benefit greatly from community-led cryospheric (permafrost, glacier, and snow) monitoring focused on flood prediction, water availability, and streamflow conditions in the hamlet catchment area. Incorporating modern skill sets, state-of-the-art technology, and traditional knowledge gained from over six decades of experience living in the high Arctic will provide the Inuit with the capacity to adapt to their changing environment.

5.3.2: Future changes in streamflow

This section summarizes the projected changes in streamflow magnitude and timing from studies in Canada. These projections were primarily obtained by using a cascade of models, consisting of an ensemble of GCMs or RCMs, statistical downscaling, and hydrologic models of individual watersheds (Figure 5.6). A few studies used outputs directly from RCMs without further downscaling and bias correction. Unless otherwise stated, the summarized projections are based on the CMIP5 GCMs, consisting of a combination of very high (RCP8.5) and intermediate (RCP4.5) emissions scenarios. The results are either for streamflow (routed flow at the outlet of the watershed, expressed in cubic metres per second) or runoff (water flowing from the watershed to streams and rivers, expressed in millimetres or metres), depending on the study.

Figure take-away: Estimating future changes in streamflow requires a cascade of models and methods.

Figure 5.6: Diagram of the cascade of models and methods involved in translating projections from global to regional to watershed scales. A typical configuration consists of outputs from an ensemble of global climate models (GCMs) (such as for precipitation and temperature) under multiple emissions scenarios, which are downscaled and bias-corrected using either statistical downscaling, or regional climate models (RCMs) and statistical downscaling, and which then are used as inputs to the hydrologic model. Hydrologic projections (such as for streamflow and snow water equivalent) on a watershed scale are derived from hydrologic model outputs.

5.3.2.1: Streamflow magnitude

CCCR2019 found increases in future annual flows across northern regions of Canada (Bonsal et al., 2019). These increases are consistent with the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) Working Group I (WGI) (Douville et al., 2021) and Working Group II (WGII) (Caretta et al., 2022) assessments of increased future annual runoff and discharge in northern-latitude regions. Recent studies of northern-latitude rivers in Canada also project increases in annual streamflow and runoff (Rawlins & Karmalkar, 2024; Stadnyk et al., 2021), reinforcing these assessments.

Across Canada, projected changes in annual runoff are highly varied, with larger increases in runoff expected on the west and east coasts and in northern Canada, and smaller increases or decreases in southern and central Canada, following a similar pattern of changes in precipitation (Arora et al., 2025). Specifically, in western Canada, river basin–scale studies using CMIP6 intermediate (SSP2-4.5) and very high (SSP5-8.5) emissions scenarios project increases in annual flow for the northward-flowing Mackenzie River (Zhang et al., 2023) and its tributaries, including the Liard (Shrestha et al., 2019), Smoky (Rokaya et al., 2020), and Athabasca (Chernos et al., 2020) rivers, and for the eastward-flowing Saskatchewan River and its tributaries (Anis & Sauchyn, 2021; DeBeer et al., 2021; Fang & Pomeroy, 2023; He & Pomeroy, 2023). An increase in annual flow is also projected for Havikpak Creek, which drains a small continuous permafrost watershed in the Northwest Territories (Krogh & Pomeroy, 2019). For the southward-flowing rivers in western Canada, annual flow is projected to increase in the Fraser River Basin over the coastal mountains, with few changes elsewhere (Islam, Curry, et al., 2019), and to increase generally at all locations in the Columbia River Basin (Chegwidden et al., 2019). Projected changes in annual flow in the Nelson and Churchill river basins indicate some variability in upstream or downstream sub-basins, with increases in the Assiniboine River and its tributaries (Anis & Sauchyn, 2022; Dibike et al., 2021), small increases or decreases in the lower Nelson River (Kim et al., 2022), and increases in total flow draining to Hudson Bay (MacDonald et al., 2018). Annual runoff and net basin supplies are projected to increase across all of the Great Lake basins (Superior, Michigan-Huron,^{Footnote 3} Erie, and Ontario) (Mailhot et al., 2019; Shrestha et al., 2022), and the Groundhog River in northern Ontario, which drains into Hudson Bay (Champagne et al., 2023). However, a decrease in the annual runoff volume is projected in the Richelieu River Basin, which drains into the Saint Lawrence River in southern Quebec (Lucas-Picher et al., 2021). This decrease is consistent with an earlier study that projected decreases in average annual flow in southern Quebec, along with the increases in northern Quebec (Lachance-Cloutier et al., 2015). Overall, while the river basins in northern Canada are projected to experience increases in annual streamflow and runoff, some of the southern and eastern river basins could experience decreases in annual streamflow and runoff.

Projected streamflow changes for 10 selected river and lake basins in Canada at the global warming levels (GWLs) of 1.5 to 4.0°C indicate generally consistent annual and winter average streamflow and runoff increases, with progressively larger increases at higher GWLs (Figure 5.7). The basins were selected from available studies, which have consistent projections for the GWL-based analysis, with naturalized flows (effect of reservoir regulation removed) considered for the Peace, Fraser, and Columbia river basins, and flows from all rivers aggregated for assessing the combined response for each of the four Great Lake basins. The median annual projections for the 10 basins show relatively small streamflow and runoff increases at GWL 1.5°C, and progressively larger increases from GWL 2.0 to 4.0°C, compared to the reference period of 1981 to 2010. Similarly, the winter (December-January-February) streamflow and runoff projections show progressively larger increases with higher GWLs across all basins, while the percentage changes are amplified because flow values are relatively small in the reference period. The spring (March-April-May) streamflow and runoff projections vary by region, with large increases for western Canada’s five mountainous basins (Liard, Peace, Fraser, Columbia, and North Saskatchewan), no change or smaller increases for the four Great Lake basins, and no change for the Saint John River Basin. The summer (June-July-August) streamflow projections for the five basins in western Canada decrease successively from 1.5 to 4.0°C. In contrast, summer runoff projections show a small increase or no change for the four Great Lake basins, and a small decrease for the Saint John River Basin. There is no consistency in the change in fall (September-October-November) streamflow and runoff projections, with progressively larger increases with higher GWLs for the Liard, Peace, and Saskatchewan river basins, and smaller increases or decreases, or no change for the other seven basins.

Overall, the increases in winter average streamflow and runoff are the largest and most consistent projected seasonal changes across Canada (Figure 5.7). Previous studies have associated these changes to the increased contribution of winter rainfall to runoff due to precipitation and temperature increases (Islam, Curry, et al., 2019; Shrestha et al., 2019; Stadnyk et al., 2021) and increased subsurface flow due to shrinking seasonally frozen soil and permafrost (Lilhare et al., 2022; Rawlins & Karmalkar, 2024). Projected changes for spring, summer, and fall are less consistent across eastern Canada, but generally consistent across the five basins in western Canada. The projected increase in spring streamflow in western Canada has been linked to earlier snowmelt-driven runoff and increased spring precipitation (Chegwidden et al., 2019; Scheepers et al., 2018; Shrestha et al., 2019), while the projected decline in summer streamflow has been linked to a combination of factors, including shallower winter snowpack, earlier onset of snowmelt, reduced summer precipitation, and increased evaporation due to higher temperatures (Bonsal et al., 2020; Chegwidden et al., 2019). Particularly, a severe decline in winter snowpack or snow drought, as projected for southwestern Canada’s watersheds (Dierauer et al., 2019; R. R. Shrestha, Bonsal, Bonnyman, et al., 2021) (Chapter 6, section 6.2), could lead to changes in spring and summer flows, a decline in the seasonal variability of annual flow cycle (Arora et al., 2025; Stadnyk et al., 2021), and summer streamflow drought (section 5.6). In addition, future changes in glaciers and permafrost (Chapter 6, sections 6.5 and 6.7) can be expected to influence future streamflow. Potential implications of these changes could include a shift in the timing of water supply away from the summer months, when water demands are highest (Bonsal et al., 2020; Immerzeel et al., 2020). Furthermore, projected increases in winter streamflow could lead to a higher chance of winter flooding (section 5.7). Note that these changes, namely increases in air temperature and diminished cooling influence of snowmelt and glacier runoff, are also impacting river temperatures, which ultimately affects river ecosystems (Box 5.2).

Figure take-away: Annual and winter average streamflow increases are the largest and most consistent projected changes in streamflow across Canada.

Figure 5.7: Summaries of annual, winter (December-January-February, DJF), spring (March-April-May, MAM), summer (June-July-August, JJA), and fall (September-October-November, SON) hydrologic projections from various studies, based on a cascade of models as shown in Figure 5.6. CMIP5 global climate models (GCMs) were used. The illustrated projections include seven GCM-driven simulations for the Liard River Basin (R. R. Shrestha et al., 2019); six for the Peace, Fraser, and Columbia river basins (Schnorbus, 2020; Schoeneberg & Schnorbus, 2021); three for the four Great Lake basins (Superior, Michigan-Huron, Erie, and Ontario) (N. K. Shrestha et al., 2022); and 15-member CanESM GCM ensembles for the North Saskatchewan (Anis & Sauchyn, 2021) and Saint John (Budhathoki et al., 2022) river basins. The circles and triangles represent individual GCM-driven hydrologic model runs for intermediate (RCP4.5) and very high (RCP8.5) emissions scenarios, respectively, with black squares indicating median values, and the red arrows at the top (Peace and Fraser) indicating the presence of outliers outside of the figure range. Global warming levels of 1.5°C, 2°C, 3°C, and 4°C are calculated relative to the pre-industrial period (approximated in this report as 1850 to 1900), and changes are shown relative to the reference period (1981–2010).

Box 5.2: River water temperature changes and implications

River water temperature change is considered a gauge of how the warming climate and human activities are affecting river ecosystems’ health and services (Ficklin et al., 2023). In the context of a warming climate, a rise in summer river temperature is considered a key indicator of climate influence associated with the compounding effect of warmer air temperatures, lower streamflow, and diminished cooling from snowmelt (Mantua et al., 2010; Yan et al., 2021). This box summarizes past and future changes in river water temperatures from studies in Canada, along with potential implications. Water temperature trends have mostly been increasing around the world, according to the IPCC AR6 WGI assessment (Parmesan et al., 2022), and several studies have documented consistent rises in river temperatures across much of Canada. The documented past trends include July–September average increases of approximately 0.14°C per decade (1950–2015) in the Fraser River (Islam, Hay, et al., 2019), July–August average increases of 0.05 to 0.22°C per decade (1960–2012) across 17 stations in western Canada (Shrestha & Pesklevits, 2023), average increases of approximately 0.27°C per decade (1960–2007) in the Saint Lawrence River (Hudon et al., 2010), and average increases of approximately 0.16°C per decade (1979–2013) at the outlets of the pan-Arctic rivers (Park et al., 2017). Consistent upward trends in summer (June–September) river temperatures have also been documented for 106 stations across Canada, with median trends of 0.18°C, 0.20°C, 0.19°C, and 0.33°C per decade (1980–2018) for June, July, August, and September, respectively (Shrestha et al., 2024). Overall, 83 out of 106 stations have statistically significant rises in water temperatures at the 10% level (meaning there is ≤ a 10% chance of concluding that an effect or trend exists when it does not) for the combined summer season (June–September), with a median trend of approximately 0.22°C per decade (Box 5.2 Figure 1). Additionally, statistically significant increases were identified for the seven-day maximum temperatures and the occurrences above the critical 18°C and 20°C thresholds (according to the tolerance limits of cold-water species) for about 30 to 65% of stations. The southeast, coast, and northern prairies were determined as the regions of highest vulnerability because of the potential impacts of rising summer water temperatures on cold-water aquatic species (Shrestha et al., 2024). Projected changes in river temperatures, available for a few river systems in Canada, indicate that warming trends will continue. For instance, according to CMIP6 ensemble simulations with a very high emissions scenario (SSP5-8.5), summer water temperature in the Nechako River (Fraser River tributary) is projected to rise on average by 2.6°C in 2041–2070 and 3.6°C in 2071–2100, compared to 1980–2010 (Gatien et al., 2024). The river is also projected to experience an increasing occurrence of water temperatures above the 20°C threshold in the two future periods (Gatien et al., 2024; Khorsandi et al., 2023). Similarly, annual water temperature in the Athabasca River is projected to rise on average by 0.8–1.1°C in 2021–2060 and 1.6–3.1°C in 2061–2100, with June–August increases ranging from 2.0–2.9°C in 2061–2060 and 3.3–7.4°C in 2061–2100, compared to 1982–2013 (Du et al., 2019). The Saint John River’s water temperature is projected to rise by approximately 1°C by 2070–2074 and further approximately 1°C by 2095–2099, compared to 2010–2014, according to an ensemble of CMIP5 models and older GCM-driven simulations. Overall, given the projected rise in air temperature in Canada (Chapter 3, section 3.4) and the strong relationship between air and water temperatures (Shrestha et al., 2024), higher future river water temperatures can be expected in summer, which could have substantial implications for already thermally stressed river systems. A rising summer water temperature could affect ecosystems and physical processes. For example, increasing exposure of cold-water species (such as salmon and trout) to higher water temperatures has been associated with shifts in their migration patterns, their increasing reliance on thermal refuges (patches of colder water), and their high mortality rates in the Fraser and Columbia rivers in western Canada and the United States. Rising water temperatures in the Great Lakes region could result in an expansion in the range of warm-water fish species, a northward shift in the range of cool-water fish species, and a contraction in the range of cold-water fish species, disrupting the ecosystem balance in river and lake systems (Van Zuiden et al., 2016). Related to warming river temperatures is a potential expansion in the range of invasive aquatic species, whose distribution may be currently limited by cold temperatures (Gervais et al., 2020; Smith et al., 2012). Furthermore, if rising river water temperatures extend into the Great Lakes, it could inhibit the mixing of lake waters, increase oxygen depletion, promote the growth of harmful algal blooms, and lead to a decline in cold-water species (Lam & Dokoska, 2022). Rising river temperatures also lead to increased heat fluxes to the oceans where they discharge, which could affect ocean stratification and circulation, and exacerbate sea ice cover loss, for example, across the Arctic shelves (Nummelin et al., 2016; Park et al., 2020). Figure take-away: Summer water temperature has been rising in most rivers across Canada.

Box 5.2 Figure 1: Map of trends in summer (June–September) river water temperature across Canada over the period from 1980 to 2018. The plus (+) sign indicates significant upward trends at the 10% significance level (meaning there is ≤ a 10% chance of concluding that an effect or trend exists when it does not) for 83 out of 106 stations across Canada. No significant downward trends were detected. Adapted from: Shrestha et al (2024).

5.3.2.2: Streamflow timing

Results from CCCR2019 indicated that in the future, the snowmelt-driven peak streamflow timing will shift to earlier (Bonsal et al., 2019). Subsequent studies continue to provide consistent results on future shifts in timing to earlier peak flows across different regions of Canada, including in western Canada in the Liard (Shrestha et al., 2019), Smoky (Rokaya et al., 2020), Athabasca (Chernos et al., 2020), Mackenzie (Scheepers et al., 2018), Fraser (Islam, Curry, et al., 2019), Columbia (Chegwidden et al., 2019), and North Saskatchewan (Anis & Sauchyn, 2021) river basins. Likewise, projections from available studies indicate shifts in timing to earlier peak flows in central and eastern Canada, including for the Assiniboine River, which flows into Lake Winnipeg (Anis & Sauchyn, 2022); multiple rivers that flow into the Great Lakes (Byun et al., 2019); the Groundhog River, which drains into Hudson Bay (Champagne et al., 2023); and the Acadie River, in southern Quebec (Aygün et al., 2020). Early peak streamflow timing and the associated early peak snowpack timing (Dibike et al., 2018; Islam, Curry, et al., 2019) are both primarily driven by increasing temperature (Shrestha et al., 2019). These changes in snowpack and streamflow could lead to a streamflow regime change, for example, a transition from a snowmelt-dominated regime to a mixed rainfall- and snowmelt-dominated regime, as projected for the Fraser River Basin (Islam, Curry, et al., 2019), the Assiniboine and Red river basins (Shrestha, Bonsal, Kayastha, et al., 2021), and the Acadie River Basin, in southern Quebec (Aygün et al., 2020). Furthermore, the early snowpack loss and peak streamflow timings have been associated with changes in streamflow predictability, which could have implications for future water resource management and flood prediction (Shrestha et al., 2022; Tsuruta & Schnorbus, 2021).

5.3.3 Confidence terms in key messages: summary of evidence

Key message 5.2: The greatest changes in streamflow magnitude across Canada have occurred and are projected to continue to occur on a seasonal basis. During the last 50 to 70 years, streamflow amounts have increased in winter and spring, and in some areas have decreased during summer (high confidence). Winter increases are projected to continue across the entire country, while summer decreases are projected across western Canada (high confidence).

Key message 5.3: Annual streamflow amounts have increased in regions of northern Canada dominated by permafrost and will continue to do so (high confidence). No long-term historical or projected changes in annual streamflow are evident across the rest of the country (high confidence).

Key message 5.4: The timing of spring peak streamflow has shifted across Canada to earlier in the season because of the earlier onset of spring freshets. This shift has resulted in changes from more snowmelt-dominated streamflow regimes to rainfall-dominated regimes. These changes are projected to continue (high confidence).

The first statement in Key Message 5.2 is a statement of fact based on many regional studies that document changes in both past and future streamflow across Canada on a seasonal basis. For all three key messages, we have high confidence in historical seasonal streamflow changes, namely, (i) increased winter and spring flows and decreased summer flows in some regions, (ii) shifts to earlier spring freshets and resulting changes from more snowmelt-dominated streamflow regimes to rainfall-dominated regimes, and (iii) increases in annual flows in regions of northern Canada. This high confidence is based on the high level of agreement among many regional and a few national studies that examined past changes in the timing and magnitude of streamflow over the last several decades. This confidence is also high because the changes are consistent with past winter and spring warming (Chapter 2, section 2.4) and resulting changes in the cryosphere, including less snow at higher elevations, which often sustains early summer runoff when this snow typically melts (Chapter 6, section 6.2).

Our high confidence in continued future changes in winter and annual flows, earlier spring freshets, and shifts from more snowmelt-dominated streamflow regimes to mixed or rainfall-dominated regimes is based on many regional studies that use a variety of hydrologic and climate models with a range of emissions scenarios or warming levels, which provide consistent evidence for these changes (see, for example, Figure 5.7). The high confidence is also based on the projections of continued warming (Chapter 3, section 3.4), and the resulting reduced snow cover and mountain glaciers and increased permafrost thaw (Chapter 6). Our high confidence in future summer streamflow changes being mainly across western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) is based on all studies showing summer decreases in western Canada, but mixed results elsewhere in the country.

5.4: Surface water levels – lakes and wetlands

Key message 5.5: Over the period of observation, there is no indication of long-term changes in water levels in lakes and wetlands for Canada as a whole, and considerable regional and temporal variability is apparent. Levels are projected to decrease in some regions and increase in others (medium confidence) because of the many complex factors that affect surface water storage. These factors include ice cover duration, open-water evaporation, increased precipitation, and permafrost thaw and associated lake drainage or lake expansion.

Canada has more than 875,000 lakes with a surface area greater than 0.1 km², accounting for approximately 62% of the world’s lakes by number, 32% by area, and 7% by volume (Messager et al., 2021). The distribution of permanent bodies of water is concentrated mostly in central-eastern and northern areas of the country (Figure 5.8). Wetlands, that is, ecosystems where terrestrial and aquatic regions meet, cover approximately 13% of the Canadian terrestrial surface and represent close to 25% of the world’s wetlands.

Figure take-away: Canada has an abundance of surface freshwater contained in bodies of water ranging in size from less than 1 km² to more than 80,000 km².

Figure 5.8: Map of the distribution of bodies of surface water of varying size across Canada, based on the HydroLAKES Global database (Messager et al., 2021). Numbered lakes refer to 1) Lake Ontario, 2) Lake Erie, 3) Lakes Michigan and Huron, 4) Lake Superior, 5) Lake Winnipeg, 6) Lake Athabasca, 7) Great Slave Lake, and 8) Great Bear Lake.

Lakes and wetlands provide invaluable ecosystem services for humans through provisioning (water source, transportation, recreational activities, food sources, etc.), regulating (carbon storage, water storage, climate moderation, etc.), cultural services (advancement of people, etc.) and supporting services (underlying natural processes, etc.). Lakes and wetlands are important to the entire water cycle (figures 5.1 and 5.9) and provide a nature-based solution to floods and droughts in Canada (Wu et al., 2023). The Great Lakes play a vital role in the regional weather and climate of Ontario and make it possible for ships to carry goods coming from the Atlantic Ocean through the Saint Lawrence River system and deep into Canada. The Great Lakes and other bodies of water across Canada are becoming increasingly vulnerable to a variety of drivers of change in the form of climate variability, climate change, hydrological change, and human-induced alterations. Smaller lakes and wetlands are especially responsive to local climate conditions.

Figure take-away: Lakes and wetlands are connected to the entire water cycle and are important to ecosystems and humans. Climate change is influencing several components of these connections.

Figure 5.9: Diagram showing how the water and energy balances of lakes and wetlands are influenced by a changing climate (precipitation and temperature). In particular, a shorter ice cover season and rising air and water temperatures influence evaporation rates, with implications for surface water storage (for example, decreased water availability) and related ecosystem services (for example, inability to access potable water). Adapted from: Woolway et al. (2020).

Water availability is crucial for all the services that lakes and wetlands provide. Key components of water availability in a hydrologic system are the amount of water in storage and the variability of that amount. The water balance of lakes and wetlands is governed by a simple equation:

Inputs minus Outputs = Change in storage [water level or net basin supply] where inputs include river inflow, direct precipitation onto the water body, and groundwater inflow, and outputs include river outflow, loss from evaporation, and exchange with groundwater.

Change in storage is typically assessed by measuring water level, which is an important indicator of climate change. In the absence of such ground-based measurements of water levels, remotely sensed observations of water surface area can be used as an indicator to assess change in the amount of surface water on the landscape and in a given body.

In Canada, fewer than 600 lakes are currently monitored for water level by the National Hydrometric Network , and nearly 50% of these lakes are influenced by some form of human alteration (regulation of water depth), such as the storage and release of water for the production of hydroelectricity, control of lake water depth for ship transportation, and the diversion of water into or out of systems. Wetland water level monitoring is predominantly carried out by focused studies of limited time spans at select sites. Monitoring programs run by local organizations are helping to fill gaps in Canada’s national observation network, particularly in under-monitored areas. For example, the Red River Métis have set up a community-based climate-monitoring program to weave Western science with Red River Métis Knowledge in monitoring climate and ecosystems, including wetlands (Case Story 5.2). However, even with these programs, producing a Canada-wide assessment of past trends and projected changes is challenging because of the country’s huge expanse.

The advent of satellite remote-sensing platforms with high-resolution spatial resolution makes it possible to monitor water surface extent (an indicator of the amount of water on the landscape), while global lake-modelling studies make it possible to simulate changes in water storage more broadly. This section focuses on major lakes and bodies of water, and reflects the available literature and monitoring data since CCCR2019 was released (Bonsal et al., 2019).

Case Story 5.2: Red River Métis Community-Based Climate Monitoring Program

The Manitoba Métis Federation, the National Government of the Red River Métis, is the democratically elected self-government representative of the Red River Métis and is duly authorized by Red River Métis Citizens to advocate for and protect their rights, claims, and interests. One of the authors is a Red River Métis Citizen, and both authors are staff within the National Government’s Department of Energy, Infrastructure and Resource Management.

Recommended citation:

Gisiger, C., Combe, P., & Manitoba Métis Federation (2026). Red River Métis Community-Based Climate Monitoring Program [Case Story 5.2]. In Canada’s Changing Climate Report 2026. (pp. xx–xx). Government of Canada. DOI for the chapter.

Through its Environment and Climate Change Portfolio, the Manitoba Métis Federation (MMF) is mandated to engage Red River Métis Elders, Youth, and Citizens to explore the impacts of climate change while promoting climate education, land-based learning, and intergenerational knowledge transfer. Red River Métis Elders, land users, and knowledge holders have long observed shifts in local weather, ecosystems, and seasonal patterns. In response, the Red River Métis Community-Based Climate Monitoring (MCBCM) program was created to integrate Western science with Red River Métis Traditional Knowledge in addressing climate change across the National Homeland. The MCBCM program equips Red River Métis Citizens with training, equipment, and resources to monitor environmental conditions in their Region. By tracking key climate and ecological indicators, the program fosters environmental literacy, strengthens community resilience, and helps fill gaps in Canada’s national climate observation network, particularly in rural and remote areas.

The MCBCM program enhances understanding of local climate impacts by engaging Red River Métis Citizens as primary data collectors, empowering them to become Citizen Scientists within their Regions (Case Story 5.2 Figure 1). Through the Wetland Monitoring stream, participants assess ecosystem health by observing bird and amphibian activity, sampling benthic invertebrates, and recording plant composition and abundance, including the presence of species at risk, invasive species, and traditionally harvested plants. These indicators offer valuable insights into how ecosystems are responding to shifts in temperature and precipitation patterns. The Water Quality Monitoring stream includes collecting grab samples, measuring turbidity, and conducting eDNA sampling to detect nutrient fluctuations and watershed stress linked to changing climate conditions. During the winter, Citizen Scientists perform snow depth and core sampling alongside wildlife tracking to gather data on snowpack variability and seasonal species behaviour. These multi-season, place-based observations generate fine-scale data that help fill critical gaps in understanding how climate change is affecting local landscapes and ecosystems, while also grounding scientific research in the Traditional Knowledge and lived experience of Red River Métis land users.

Case Story 5.2 Figure 1: Red River Métis Citizens contribute to the Red River Métis Community-Based Climate Monitoring Program (MCBCM) by collecting samples to assess a) benthic invertebrates, and b) water quality. The MCBCM program equips Red River Métis Citizens with training, equipment, and resources to monitor environmental conditions in their Region while also grounding scientific research in the Traditional Knowledge and lived experience of Red River Métis land users.

Data collection across all MCBCM activities follows standardized protocols and is submitted through an online survey platform, enabling broad participation across MMF Regions, including Red River Métis Citizens living beyond borders. Each survey also provides opportunities to share oral histories and site photos, recognizing that Traditional Knowledge is deeply connected to the land and environment. To support consistency and accessibility, the MMF has developed field guidebooks and publicly available training videos. On-call field support is available from MMF staff, and participants are compensated for each completed survey, acknowledging the value of their time, effort, and knowledge. This approach ensures that data are both scientifically rigorous and grounded in the cultural context and land-based experience of Red River Métis Citizen Scientists. Data gathered through the MCBCM program feed into local land-use planning, supports MMF decision-making, and contributes to Canada’s understanding of regional climate impacts, particularly in under-monitored areas.

By providing Red River Métis Citizens with valuable opportunities to engage in climate monitoring, the MCBCM program serves as a leading model for Indigenous-led environmental stewardship. It addresses the critical need for localized climate data while offering a culturally relevant approach to climate literacy and adaptation. The program contributes essential data to national and global efforts to understand and respond to climate change, while reinforcing the Red River Métis’s inherent role in environmental stewardship. This model demonstrates how Indigenous knowledge systems and Western science can be woven together to generate more holistic, resilient, and actionable responses to climate change.

5.4.1: Large lakes of Canada

Canada is covered by several “great lakes” that formed along the Canadian Shield (Figure 5.8). The five Great Lakes (Superior, Michigan, Huron, Erie, and Ontario), located in the east-central interior of North America, are a series of large, interconnected bodies of freshwater that connect to the Atlantic Ocean through the Saint Lawrence River system. Given their importance to the North American economy and people, these lakes are among the most studied bodies of water on the continent. Water levels of these lakes have been monitored for more than 100 years by Canadian and United States agencies. Although less studied, equally important are Lake Winnipeg, Lake Athabasca, Great Slave Lake, and Great Bear Lake, located to the west and north of the Great Lakes.

5.4.1.1: Past changes

CCCR2019 stated that the water levels on the Great Lakes exhibited a large degree of variability over the historical period because of natural climate variability (Bonsal et al., 2019). Year-to-year and multi-year fluctuations (wet and dry cycles) can be seen in the data for 1930 to 2022 regarding the annual peak 30-day (one-month) average water level, which typically occurs during the summer (Figure 5.10). These peak 30-day average water levels were also used to extend the series back to the early 20th century for all the lakes examined in this section because winter water levels were not available for the more northern lakes prior to the 1960s. The data on these annual peak levels also enable the examination of key hydrological extremes that impact shoreline erosion, flooding of property, navigation, recreation, the economy, aquatic ecosystems, and human health.

Figure take-away: Large-lake water levels show a lot of variability and abrupt shifts over a 90-year record.

Figure 5.10: Past annual peak 30-day average water level anomaly (divergence from the 1961–2000 reference period) in metres for a) Lake Superior, b) Lake Michigan-Huron, c) Lake Erie, d) Lake Ontario, e) Great Bear Lake, f) Great Slave Lake, g) Lake Athabasca, and h) Lake Winnipeg. This figure updates and modifies time series information found in multiple sources (see below) using daily data obtained from the Water Survey of Canada and the National Oceanographic and Atmospheric Agency. An asterisk (*) next to the lake name indicates that water levels were influenced by regulation. Note that the Anomaly axis scales differ among the various lakes. Adapted from: Bonsal et al. (2019); ECCC and GNWT (2020); Gibson et al. (2006); Kerr (1985); MacDonald et al. (2004); McCullough (2015); NOAA (2024); Peters and Buttle (2010); NOAA (2024).

Divergences (increases and decreases) in annual peak water level for the Great Lakes ranged from approximately plus or minus 0.5 to 1 m from the long-term baseline (1961–2000) (Figure 5.10a–d). Of note, since the release of CCCR2019, lakes Superior, Michigan-Huron, and Erie have rebounded from an extended period of low water levels to near record or record high water levels in recent years. In addition to increasing net inflow to the lakes, over-lake precipitation rose while over-lake evaporation fell rapidly after 2014, setting the stage for the recent surge in water levels (Gronewold et al., 2021). High water levels on the Great Lakes can cause shoreline erosion, flooding, and property damage (David, 2019), while lower water levels force ships to reduce their cargo tonnage (resulting in increased shipping costs) and affect both the usability of infrastructure, such as docks and piers, and shoreline ecosystems. Of all the lakes, only Erie and Ontario exhibited a significant change in peak water levels over the 90+ years (at the 5% significance level, meaning there is ≤ a 5% chance of concluding that an effect or trend exists when it does not). The estimated trends are in the order of an increase of approximately half a centimetre per year (0.6 and 0.4 cm/yr, respectively) (Mann-Kendall trend test outlined in Peters et al., 2022).

Less well known to the international community and less studied are the other large lakes of Canada that are of similar size to the Great Lakes. These are Great Bear Lake (the biggest lake entirely within Canada); Great Slave Lake (the deepest lake in North America); Lake Athabasca, in the Mackenzie River system, which empties into the Beaufort Sea; and Lake Winnipeg, which drains into Hudson Bay through the Nelson River system and contributes important volumes of water to the Arctic Ocean. Canadian agencies have monitored the water levels of these lakes for more than 90 years. However, except for Great Bear Lake, these lakes are all influenced by some form of human alteration and regulation, making it difficult to assess climate-related influences and trends.

Divergences in annual peak water level ranged from approximately plus or minus 0.5 m for Great Bear and Great Slave lakes, with a notably larger range in divergences for lakes Athabasca and Winnipeg (Figure 5.10e–h). As with the Great Lakes, studies show Great Bear and Great Slave lakes, and lakes Athabasca and Winnipeg have experienced periods of high and low water levels driven by regional climate conditions (ECCC & GNWT, 2020;. Gibson et al., 2006; MacDonald et al., 2004; Peters et al., 2006; Sauchyn & St-Jacques, 2016). Substantial variability in annual peak water level occurred in all the lakes during the historical period shown in Figure 5.10. For instance, since CCCR2019, Lake Athabasca and Great Slave Lake have experienced a shift from an extended period of below-normal water levels to some of their highest ever-recorded water levels in the 2020s. In fact, the summer of 2020 water levels were unprecedented on Great Slave Lake, which instigated a multi-agency hydrological analysis to find the cause of high concentrations of suspended sediments in the lake that were clearly visible from space and a concern to local people. The analysis found that they were driven primarily by snowmelt and heavy rainfall in the Mackenzie River headwaters that generated above-normal direct inflow into the lake. Overall, no significant long-term trends (at the 5% significance level, meaning there is ≤ a 5% chance of concluding that an effect or trend exists when it does not) were discerned for annual peak storage on Lake Athabasca, Great Slave Lake, and Great Bear Lake over the years spanning 1930 to 2022.

5.4.1.2: Future changes

Since the assessment of future lake levels in CCCR2019 (Bonsal et al., 2019), future Great Lake water levels have been projected in relation to an increase of 1.5 to 3.0°C in global average temperature (Figure 5.11; Chapter 3, Box 3.1) (Seglenieks & Temgoua, 2022). The results show the same general message as that of previous water level studies: projected average water level may be lower or higher, depending on which climate models are used. A key finding from Figure 5.11 is that there is expected to be greater variability in projected water levels, with more extreme-high and extreme-low water levels possible in the future. This projection aligns with results from other studies investigating changes in net basin supply^{Footnote 4} extreme events, which concluded that in future warmer climates, lakes are likely to experience more severe and frequent net basin supply minimums and maximums, as well as more variable annual cycles (Mailhot et al., 2019; Music et al., 2015).

Figure take-away: The variability of lake levels in the Great Lakes increases with higher levels of warming.

Figure 5.11: Box and whisker plots of projected annual average lake level anomalies (divergences from the 1961–2000 reference period) in metres under global warming levels of 1.5°C, 2.0°C, 2.5°C, and 3.0°C for a) Lake Superior, b) Lake Michigan-Huron, c) Lake Erie, and d) Lake Ontario. The average divergence in water level is shown by the yellow line inside the box, the statistical range in water level is the 25th to 75th percentiles at the top and bottom of the box percentiles, and the extreme water levels are shown by the lines extending from the box (whiskers) that represent the 90th percentiles in the datasets. Adapted from: Seglenieks and Temgoua (2022).

Unlike for the Great Lakes, no studies have been published since CCCR2019 to address future changes in water levels in Great Bear Lake, Great Slave Lake, Lake Athabasca, or Lake Winnipeg. This lack of studies adds uncertainty when informing Canadians and people living in Canada and when developing adaptation strategies. Continental-scale hydrological simulations using CMIP5 models with intermediate (RCP4.5) and very high (RCP8.5) emissions scenarios suggest that lakes Athabasca and Winnipeg will be influenced by higher winter baseflows and earlier spring inflows by the end of the 21st century (Arora et al., 2025). Only focused lake-modelling investigations can determine how such projected changes in streamflow timing and magnitude will dynamically interact with a warming climate and what their impacts will be on lake ice duration, water temperatures, open-water evaporation rates, and water storage. Such studies are necessary to understand the impacts of competing hydrological forces on large freshwater systems in an era of climate change (Gronewold et al., 2021).

5.4.2: Other lakes – water level, storage, and extent

5.4.2.1: Past changes

It is impossible to monitor the more than 875,000 lakes in Canada using traditional ground-based hydrometric stations that provide observations of daily water levels. However, the advancement of hydrological models to simulate individual lakes’ water balances (such as water storage or levels) and the use of satellite observations to determine water surface areas both provide opportunities to examine past changes in lake and wetland conditions over several decades across Canada.

Water levels are typically used to assess the effect of climate change and variability on storage. However, when such measures are not readily available, for example, because of a lack of stations, the change in individual lakes’ water storage can be assessed over time using a combination of information. For instance, a recent global study (Yao et al., 2023) using remotely sensed data, climate data, and hydrological models provides information on trends in lake storage for the period from 1992 to 2020 for approximately 530 natural lakes and reservoirs distributed across most of Canada. Results indicate that over this nearly 30-year period, approximately 34% of the lakes experienced statistically significant water storage decline (significant at the 5% level, meaning there is ≤ a 5% chance of concluding that an effect or trend exists when it does not) compared to approximately 16% that experienced gains in water storage (Figure 5.12). The upward trends in lake storage are concentrated in the Prairies and the downward trends are mainly distributed across the Arctic. Although these percentages are lower than what were reported globally, the ratio of downward to upward trends (approximately 2:1) is in line with the global results (Yao et al., 2023). On the global scale, the net volume loss in natural lakes was reportedly largely due to climate warming, rising evaporative demand, and human water consumption. This conclusion would also apply to lakes and reservoirs in Canada, but other causal factors need to be considered, such as the degradation of the cryosphere, which disproportionately affects northern latitudes (Box et al., 2019).

Figure take-away: For the last 30 years, there are no consistent changes in lake and reservoir water levels for Canada as a whole.

Figure 5.12: Map of lake water storage trends for 529 natural lakes and reservoirs for the period from 1992 to 2020. Upward and downward trends significant at the 5% level (meaning there is ≤ a 5% chance of concluding that an effect or trend exists when it does not) are shown as solid circles. Data source: GLWS) database of estimated lake water storage (GLWS version 1.1), developed by Yao et al. (2023).

The seasonal timing of lake ice cover (freeze-up and breakup) and water temperatures play a major role in controlling many lake processes (Figure 5.9), such as the partitioning of lake water (for example, loss of water by evaporation versus the addition of water by precipitation). Chapter 6, section 6.4.1 assesses that lake ice cover duration in parts of Canada has experienced up to an approximately four-day decline per decade over the period from 1970 to 2019. These results are consistent with a recent global study of lake ice phenology (Grant et al., 2021), that is, the seasonal phenomenon of ice freezing and thawing. This study reveals that extensive areas of Canada experienced a shortening of the ice cover season between the periods from 1981 to 1990 and 2010 to 2019. This shortening was particularly pronounced (up to ~20 days) in northern areas of the country that typically experience a longer ice season (Grant et al., 2021). The lengthening of the open-water season has the potential to increase the total amount of water lost by evaporation to the atmosphere and lead to declines in water storage and extent if the loss is not offset by more water inputs.

The above assessment of select individual lakes does not include a multitude of bodies of water, such as seasonal wetlands, that are sensitive to the prevailing climate and that experience occasional connectivity to nearby rivers and lakes as a result of ice-jam and open-water floodwater additions (Buttle et al., 2016; Peters et al., 2016). It also does not include bodies of water that are formed or lost because of long-term climate change, such as in permafrost regions. A valuable approach to assessing the influence of climate variability and climate change on past water surface conditions across the vast Canadian landscape is to use remotely sensed observations to produce maps of water surface areas. Such an assessment differs from the previous paragraphs focused on lake water level or storage in that it looks at the areal expansion or contraction of all types of surface water, including the larger lakes discussed above and other types, such as prairie wetlands, deltas, and floodplains.

A recent study by Olthof and Rainville (2022) produced a time series of surface water maps using Landsat satellite imagery covering the period from 1984 to 2019. Although relatively small in extent compared to the permanent bodies of water (such as the Great Lakes), the identified areas with significant wetting trends across the country (significant at the 5% level, meaning there is ≤ a 5% chance of concluding that an effect or trend exists when it does not) were more than five times greater than those identified with significant drying trends (Figure 5.13). According to this study, changes in water surface conditions were highly variable by region. This variable response is exemplified by zooming in to select locations. For instance, drying, wetting, and mixed responses are shown with inset maps for a tundra lakes area in the Northwest Territories, a large freshwater delta in northern Alberta, a prairie area in southern Saskatchewan, and a floodplain around the Saint John River, in New Brunswick (Figure 5.13a–d).

Figure take-away: Over the last 35 years, less than approximately 1.2% of Canada’s landmass showed significant changes in surface water area, with eastern Canada showing more water expansion than western Canada.

Figure 5.13: Landsat remote-sensing–derived map depicting areas with permanent bodies of water and areas that became significantly wetter or drier from 1984 to 2019 (significant at the 5% level (p < 0.05), meaning there is ≤ a 5% chance of concluding that an effect or trend exists when it does not). All types of surface water are captured, such as wetlands and ponds on river floodplains and in riparian zones, deltas, and the larger lakes. Inset maps show a) lake shrinkage in part of the uplands tundra lakes area adjacent to the Mackenzie River Delta, in the Northwest Territories, where permanent water is surrounded by drying areas, b) the Peace-Athabasca Delta, in northern Alberta, becoming spatially both wetter and drier, c) a prairie area in southern Saskatchewan becoming drier, and d) a floodplain in the Saint John River sector in New Brunswick becoming wetter. Adapted from: Olthof and Rainville (2022).

Permafrost degradation in Canada’s Arctic and sub-Arctic regions has been found to be an additional driver influencing water availability (Chapter 6, section 6.7) (Spence et al., 2020). Along with a warming climate, wildfire has been identified as a factor contributing to ongoing permafrost thaw (Gibson et al., 2018; Holloway et al., 2020; Travers-Smith et al., 2022). Bodies of water in permafrost regions may expand because the thaw processes that formed them have accelerated, while in other instances they may shrink and even disappear because a new outlet has led to surface drainage.

For instance, in northwestern Canada, a range of changes in water surface area have been observed in response to both climate change and permafrost degradation. These changes include increasing thaw depth and the development of retrogressive thaw slumps along shorelines that in some cases led to catastrophic drainage of lakes (Chapter 6, section 6.7) (Kokelj et al., 2023; Lantz et al., 2022). For example, in the Inuvik–Tuktoyaktuk region (6000 km²) to the east of the Mackenzie River Delta, the rate of water body drainage was observed at 1.5 lakes per year from 1984 to 2019 (Kariyawasam, 2022). Nearby and slightly to the south in the Lower Mackenzie Plain (14,631 km²), remote-sensing analyses show that the total lake area decreased by approximately 1% over a similar timeline despite increases in the area of smaller lakes driven by increasing precipitation (Travers‐Smith et al., 2021). Widespread lake drainage has important implications leading to large-scale drying in Arctic lake-rich areas, which in turn affects hydrology, water security, ecosystems, and permafrost carbon dynamics (Chen et al., 2023).

5.4.2.2: Future changes

As reported in CCCR2019, future warming and further permafrost thaw are anticipated to have a substantial effect on surface water in the northern regions of Canada. Lakes affected by permafrost thaw have natural cycles of expansion, erosion, drainage, and reformation (Van Huissteden et al., 2011), which may accelerate under warmer climate conditions and changing precipitation patterns. Simulations in Siberia (which has a similar climate to regions in northern Canada) for the years 2000 to 2100 have projected lake expansion into the 2060s, followed by decreases in lake area because of lake drainage. Such projected changes in water surface area and storage on Canada’s northern landscape will have important implications; in extreme cases, the complete drainage (loss) of certain lakes may occur.

Figure 5.9 conceptually outlines key lake variables and their response to a changing climate. For example, a shorter ice cover season and rising air or water temperatures will lead to greater seasonal evaporation, with implications for lake water storage, level, and extent. Several recent global lake studies (Wang et al., 2018; Zhou et al., 2021) provide insights into projected changes in key lake variables across Canada for the end of the 21st century. As assessed in Chapter 6, section 6.4, the onset of lake ice freeze-up is projected to occur later and breakup is projected to occur earlier, leading to a longer open-water season, especially in the more northern regions (e.g., Grant et al., 2021). Associated with these seasonal changes in ice cover dynamics are projections of warmer water temperatures and increased evaporation. It is uncertain how such changes will interact with other hydroclimatic variables (precipitation, basin runoff, etc.) and affect water surface storage in areas outside the Great Lakes and other large lakes of Canada.

These results suggest that long-term patterns of change observed in recent decades will probably not only continue, but in many cases intensify in the future (Box et al., 2019; Woolway et al., 2022). Overall, the implications of climate change on lakes and the ecosystem services they provide will have important implications for Canadians and people living in Canada. For example, communities that rely on lakes and reservoirs for water supply may become vulnerable to shifts in seasonal availability of water. Such is the case for northern areas of Canada where there is limited existing freshwater supply (Bakaic & Medeiros, 2017) and where lake ice provides key transportation routes (Woolway et al., 2022).

5.4.3: Confidence terms in key messages: summary of evidence

Key message 5.5: Over the period of observation, there is no indication of long-term changes in water levels in lakes and wetlands for Canada as a whole, and considerable regional and temporal variability is apparent. Levels are projected to decrease in some regions and increase in others (medium confidence) because of the many complex factors that affect surface water storage. These factors include ice cover duration, open-water evaporation, increased precipitation, and permafrost thaw and associated lake drainage or lake expansion.

The first statement is a statement of fact based on the assessment of observed long-term water level trends in the Great Lakes and other large lakes of Canada. These trends show that water levels have varied on year-to-year and multi-year timescales, with significant long-term upward trends found only for lakes Erie and Ontario (Figure 5.10). The first statement is also based on an assessment of simulated water storage levels in lakes and reservoirs across Canada (Figure 5.12) and Canada-wide satellite-derived data on surface water extent (Figure 5.13), which show both decreases and increases across the country in the last 30 to 40 years.

Our understanding of future lake levels and water surface extent is based on evidence from an investigation on projected changes in Great Lake levels under various warming levels (Figure 5.11), as well as on studies that examined the association between warming temperatures and various processes that impact surface water levels, including duration of ice cover, open-water evaporation, increased precipitation, and permafrost thaw. In light of this evidence, water levels are expected to fall in regions where increased evaporation (from both warmer temperatures and longer ice-free periods) exceeds increased precipitation, or where permafrost thaw is expected to increase lake drainage. Other bodies of surface water are expected to expand in regions where precipitation exceeds evaporation, and in areas of continuous permafrost where the acceleration of permafrost thaw will cause lake expansion. However, it is uncertain how such projected environmental changes will interact with other hydroclimatic variables (precipitation, basin inflows, etc.) and impact the direction, magnitude, and range of water surface storage across Canada. Therefore, we have medium confidence in our assessment of water levels, not only because of the established connection between these various processes and climate warming, but also because of the lack of studies about future water levels (except for the Great Lakes) and the complexity of factors that affect surface water levels.

5.5: Groundwater

Key message 5.6: Groundwater recharge is anticipated to occur earlier in the year across the country, largely because of earlier snowmelt and more winter rain events (high confidence). The greatest changes in groundwater systems are expected to occur in northern Canada because of thawing permafrost, which may result in new groundwater pathways (medium confidence). This would allow more interaction between deeper groundwater and surface water systems with possible effects on surface water quality.

Key message 5.7: Groundwater is expected to remain one of the more resilient freshwater resources in a changing climate in comparison to surface water (medium confidence), given its naturally slow flow and enormous storage capacity, and if extraction through pumping does not markedly increase. 

Groundwater is water stored underground in the pores, cracks, and holes in geologic formations (deposited sediments, rock), typically below the soil zone to depths of up to several kilometres, everywhere across the country. Unlike most soil water, groundwater below the water table will flow into an open hole or well. Groundwater withdrawn from aquifers (relatively permeable geologic units where groundwater flows easily) supplies drinking water to about 30% of people living in Canada, including approximately 80% of the rural population, provides water supplies to a wide range of industries, and is a key source of irrigation water used for agriculture (Canadian Council of Ministers of the Environment, 2010). Groundwater levels are naturally influenced by inputs through groundwater recharge, mainly from precipitation, irrigation, and inflows from surface waters, and by outputs through groundwater discharge into surface waters (as springs or seeps onto the land) and through evapotranspiration. Many surface water systems in Canada are strongly interconnected through shallow groundwater systems, and some lose water to recharge groundwater systems, especially in arid environments (such as the Prairies), but often they receive substantial inputs from groundwater discharge. Even small changes in shallow groundwater systems can substantially influence stream flow and water levels in wetlands and small lakes, particularly in dry periods (Murray et al., 2023). Indeed, groundwater plays an important role in sustaining baseflow for many Canadian rivers, even those within or flowing from mountainous terrain typically associated with summer glacier and snowpack melting (Hayashi, 2020). A conceptual model of groundwater flow linking recharge (through infiltration) and discharge (as with groundwater–surface water interaction) is shown in Figure 5.14a. Both recharge and discharge can be influenced by climate change. However, groundwater systems often show resilience, as the climate-induced changes in one of these two components can be somewhat mitigated by changes that result for the other component, as illustrated for climate-induced changes in recharge in Figure 5.14b,c. Similarly, declining water levels in an aquifer, such as through groundwater extraction, can lead to overexploitation. However, increasing pumping costs associated with significant lowering of groundwater levels in production wells can act to limit future extraction. The magnitude and timing of responses in groundwater to changes in climate are typically greater and more rapid for shallow groundwater systems, whereas deeper systems respond much more slowly (over a decade or longer).

Overall, groundwater tends to be more resilient than surface water to climate change because of the enormous size of the subsurface groundwater reservoir, its slow response to surface climate variations, and internal balancing of changes in inputs and outputs. This can help to both mitigate climate-induced changes in well-connected surface water through interactions between groundwater and surface water and enhance the sustainability of groundwater as a reliable water source. However, warming climate conditions in Canada’s northern landscape are resulting in rapid changes in the subsurface hydrology, which may have significant impacts on groundwater–surface water interactions in this sensitive terrain (McKenzie et al., 2021).

Groundwater is a strategic natural resource. It has intrinsic value as a source of private and municipal drinking water, and it plays a vital and diverse role in sustaining ecosystems by mitigating the impacts of climate change on surface water. However, despite its significance, there is a limited understanding of Canada’s groundwater resources, and a paucity of data required to inform its long-term sustainable management.

Figure take-away: Future groundwater recharge rates will depend on the balance between the degree of warming and whether precipitation increases or decreases. Recharge will be greater through increased precipitation and smaller temperature increases and will be lesser through decreased precipitation and greater temperature increases.

Figure 5.14: Conceptual model of groundwater flow with a near surface (depicted by long thin arrows), linking areas of groundwater recharge (through infiltration in this case, the primary natural input, shown with vertical dashed arrows) and groundwater discharge (through interaction with a surface water body in this case, the primary natural output, shown with thick short arrows). a) Base case, showing system adaptation to potential changes in groundwater recharge linked to climate change. b) Scenario 1, showing greater recharge through increased precipitation or decreased evapotranspiration. c) Scenario 2, showing lesser recharge through decreased precipitation or increased evapotranspiration. Greater recharge raises the water table in the recharge area, which leads to greater groundwater flow and subsequently greater discharge, represented by more arrows for each process, thus limiting the rise in the water table (groundwater levels). Conversely, lesser recharge lowers the water table in the recharge area, leading to lower groundwater flow and discharge, represented by fewer arrows for each process, thus limiting the decline in the water table (groundwater levels). Both scenarios illustrate the resiliency of groundwater levels to potential effects of a changing climate, as greater inputs to groundwater are countered by greater outputs (and vice versa).

5.5.1: Past changes

Climate change effects on groundwater resources in Canada have been difficult to quantify primarily because of the high degree of hydrogeologic-climate variability across the country, insufficient datasets, influences from other factors (such as pumping for domestic use and irrigation), and relatively long hydrologic response times (Bonsal et al., 2019; Costa et al., 2021). The most comprehensive regional groundwater level data are collected through the monitoring of well networks managed by provincial and territorial government authorities (for example, the Ontario Provincial Groundwater Monitoring Network and the Alberta Groundwater Observation Well Network). However, the density of well networks across Canada and the continuity of their groundwater level data are inconsistent, and not archived and evaluated at the national level (Bonsal et al., 2019; Rivard et al., 2009).

Hydrogeologists have been increasingly reliant on remote-sensing technologies, including GRACE satellites, to quantify gradual changes in groundwater storage on a national scale. According to data from the GRACE satellite missions, national trends in changes in groundwater storage from 2003 to 2016 have been highly variable (Figure 5.15). For example, storage gains of approximately 10 mm/yr have been observed in parts of Quebec and Atlantic Canada, whereas storage losses of 10–15 mm/yr have been detected across northeastern Alberta and southwestern Saskatchewan (Fatolazadeh & Goïta, 2022; Li & Wang, 2022). However, direct correlations to local changes in climate have been difficult to identify (Li & Wang, 2022). For comparison, GRACE measurements over a similar time period to that noted above have revealed decreases in groundwater storage of between 20–60 mm/yr for several areas around the globe experiencing major groundwater depletion through extensive pumping (for example, the midwestern United States, northwest India, and the North China Plain) (Famiglietti & Ferguson, 2021). This suggests that regional groundwater changes in Canada are relatively more moderate. Although there are recognized limitations to many satellite-based remote-sensing technologies, including GRACE satellites, the data provide valuable, regional-scale information that is very difficult to obtain through terrestrial measurements alone.

Figure take-away: There is a high degree of variability across Canada in past rates of groundwater storage.

Figure 5.15: Map of trends in groundwater storage rates in mm/yr across Canada for the period from 2003 to 2016 estimated from GRACE satellite data. Changes in groundwater storage were estimated by subtracting changes in soil moisture, snow, and surface water storage from changes in total water storage. The areas in white are regions that did not have sufficient data to estimate changes in storage. Source: Li and  Wang (2022).

Changes in groundwater storage have also been noted in a variety of regions using hydrographs from observation wells. However, the relationship between these variations in groundwater level and changes in the amount of groundwater storage has not been investigated in detail. Doing so would be challenging because of the range and variability of storage capacity in groundwater systems (Freeze & Cherry, 1979). Interpreting the influence of climate change on well water levels is further complicated in some areas by the effects of groundwater extraction, especially for irrigation. Such effects may increase in areas experiencing more prolonged droughts with climate warming. Also, human activities such as installing tile drainage on agricultural fields, using low-impact development for stormwater management, or implementing managed aquifer recharge (storing excess water in aquifers) moderate changes in groundwater levels that might otherwise occur with changing precipitation patterns or warming temperatures. These activities are likely to increase in the future, in part as adaptation measures to mitigate the impacts from changing climate.

The amount of groundwater in storage fluctuates constantly because of variations in climate over seasonal and decadal timescales, albeit at rates and magnitudes that tend to be much lower than those observed in surface water systems, as described above. Given the slow reaction of groundwater reservoirs to climate variability, many large groundwater systems are in a constant state of disequilibrium with the current climate conditions (Rousseau-Gueutin et al., 2013). Responses of most groundwater systems in Canada lag behind changes in climate, and the full impact of new and changing climate conditions on groundwater levels may not be fully realized for decades in much of Ontario and Quebec and millennia in parts of the Prairies and Atlantic Canada (Cuthbert et al., 2019). This slow response of regional storage in the groundwater reservoir to changes in climate demonstrates the resilient nature of the groundwater resource and illustrates the capacity of groundwater to mitigate climate impacts associated with surface water resources locally and regionally. However, the long timescales involved with groundwater system response to changes in climate emphasize the need to support long-term observation networks and to consider implications of water management decisions over decades to centuries.

The resiliency of groundwater is further manifested in its temperature conditions and related impacts on bodies of surface water through groundwater discharge. A thermal-modelling study investigating the potential effects of rising surface air temperature due to climate change on shallow groundwater found that although the shallow groundwater temperature would rise over time, this occurred at a much slower rate than surface air temperature (Kurylyk et al., 2015). Thus, shallow groundwater and discharge zones in surface water may play a crucial role in providing thermal refuge for fish and other aquatic organisms in the near future in areas experiencing more intense heatwaves. As an illustrative example, Chu et al. (2008) considered the effect of various climate change scenarios on the thermal diversity of stream fish communities (with cold-, cool-, and warm-water preferences) in 43 watersheds in southern Ontario and noted that watersheds with higher groundwater discharge had more diverse thermal regimes and fish communities and are less sensitive to climate change than those with lower discharge.

Trends in groundwater recharge over time at a regional level require the compilation of extensive datasets and have proven challenging to establish (Boumaiza et al., 2022). Research activities focusing on the impacts of climate change on groundwater recharge and storage change are being mostly conducted on local or watershed scales (e.g., Costa et al., 2021). For example, research across the Canadian Prairie region using projected climate conditions and numerical modelling tools has shown that despite increased precipitation throughout the region, average annual recharge rates may significantly decrease from 10.2–3.2 mm/yr (Negm et al., 2021), a result that illustrates how groundwater responses to changing climate conditions are not always straightforward. The most certain change across the country remains the fact that spring recharge to groundwater is beginning earlier because snowmelt is occurring earlier in the year (Bonsal et al., 2019; Larocque et al., 2019).

The most rapidly changing groundwater flow systems in Canada are in the northern landscape, where climate warming has been documented at rates over three times faster than the global average and is increasing permafrost thaw. Permafrost acts as a barrier to vertical groundwater flow, separating deep and shallow flow systems and limiting flow to the seasonally thawed active layer or through unfrozen zones in the permafrost (Figure 5.16). As permafrost thaws, changes in the near surface conditions associated with land subsidence and modifications to soil structure may influence groundwater recharge and discharge patterns. As thawing continues, new groundwater pathways form and existing pathways expand, making more active interactions possible between deep groundwater, shallow groundwater, and surface water systems (McKenzie et al., 2021). Increased connections between surface and deeper groundwater systems may provide a greater opportunity for deeper infiltration and recharge and make it possible for older groundwater (with more dissolved minerals) to discharge into surface water systems. Groundwater discharge flux into streams may also be changing, as has been documented in the Yukon where significant increases in annual minimum flows (base flow) have been observed in many streams over a recent 10-year period. Similar climate-driven hydrologic changes are likely occurring in some Canadian alpine settings that are experiencing, for example, losses of permafrost within rock glaciers (Harrington et al., 2018). Permafrost thaw is also releasing previously entombed chemical pollutants (pollutants encased in frozen sediment) that are naturally occurring or geogenic compounds (such as carbon species or heavy metals) or those that originate in waste disposal sites (such as landfill or legacy drilling sumps). These contaminants can impact groundwater quality (Box 5.3) and subsequently impair surface water quality or contribute substantially to greenhouse gas emissions (Mohammed et al., 2022).

Figure take-away: As permafrost thaws, new groundwater pathways to surface water systems form, thus affecting water quality.

Figure 5.16: A conceptual illustration of groundwater circulation and interaction with surface water features within a permafrost landscape involving complex overburden and bedrock geology. a) Conditions where the permafrost is completely continuous in lateral extent, resulting in isolation between the near surface, supra-permafrost flow, and the groundwater flow systems that underlie the permafrost (sub-permafrost flow). b)  Greater circulation between deep and shallow groundwater flow systems and surface water after the permafrost has partially thawed and is discontinuous laterally. Source: Conway-White et al. (2025).

5.5.2: Future changes

Gradual changes in groundwater recharge, subsurface water levels, and overall groundwater storage as a result of a changing climate will vary regionally across Canada and remain challenging to quantify (Bhatti et al., 2021). The same is noted on the global scale (Jasechko et al., 2024). Some advances in quantification of future changes are being made at provincial and territorial levels with the collection and synthesis of data from groundwater monitoring networks. For example, in Ontario, Markle and Harris (2019) conclude that there is no widespread, regional decline in groundwater levels in the province. However, the median length of the individual well datasets was only 10.9 years, which makes identifying climate-induced trends challenging. These datasets will become more useful in quantifying future changes in groundwater levels as the monitoring period continues to lengthen. At the federal level, the Groundwater Information Network is working to integrate provincial groundwater data (well-monitoring data, hydrogeologic mapping, etc.) to facilitate increased access to and awareness of national groundwater data and information primarily in the southern regions of Canada. Activities are also currently underway to correlate long-term well datasets with data about weather changes over time to identify trends in groundwater levels and temperature that are caused by climate change. These trends can then also be used as potential metrics for projecting the effects of climate change on groundwater.

As noted above, the response of Canada’s groundwater resources to a changing climate appears to be slow in most cases, highly variable across the country, and influenced by a complex interaction of surface and subsurface processes. Therefore, scientists are frequently relying on numerical models to provide insight into future changes in this critical water resource. Significant progress is being made in improving the predictive capability of modelling tools and in some cases understanding and reducing uncertainty in model results (Costa et al., 2021). The long-term hydrologic datasets required to inform groundwater models are being collected and compiled at a provincial level, and some provinces are making progress to provide these datasets in an open-data format for general use (for example, the Ontario Provincial Monitoring Well Network). The next generation of modelling tools are focusing on a fully integrated consideration of atmospheric, surface water, and groundwater systems (Chen et al., 2020). Large national initiatives such as the Global Water Futures Program and the Canada 1 Water Project have collated physical and hydrologic data from across Canada, again in an open-data format, and have been developing and implementing this next generation of models, which are being used to enhance the understanding of the effects of climate change on groundwater in Canada.

Although these advances in data availability and modelling hold promise for improved quantitative prediction of the future state of Canada’s groundwater resources, challenges remain because of the significant degree of model uncertainty about how climate change affects groundwater, the wide range of different subsurface materials and conditions, and the complex feedback between surface and subsurface processes (Bonsal et al., 2019; Costa et al., 2021).

In regions where climate change results in reduced surface water availability and potential overallocation of surface water resources, groundwater may be relied upon to augment supplies, including for irrigation and municipal purposes. In this future scenario, increased groundwater extraction may lead to local lowering of groundwater levels and ultimately to overexploitation where extraction exceeds replenishment. Such conditions have been observed, for example, in the High Plains Aquifer of the United States (Kromm & White, 1992) and elsewhere globally. Current evidence suggests that such conditions are limited across Canada.

Regarding the effects of climate change on northern landscapes, a new generation of modelling tools is emerging to simulate the complex movement of heat and water in the subsurface (e.g., Huang & Rudolph, 2022). The resulting information is used to understand the dynamic evolution of northern groundwater flow systems under conditions of a warming climate (Grenier et al., 2018). Supporting data to create and validate parameters for these models in this remote landscape is exceptionally difficult to obtain, which leads to considerable uncertainty about simulation results. However, the establishment of long-term field observatories across Canada’s north by territorial and federal governments along with academic institutions (e.g., Quinton et al., 2019) will support the monitoring and data collection required to reduce the uncertainty in predictive modelling of the long-term fate of groundwater flow systems in this challenging terrain.

Box 5.3: Beyond groundwater levels – climate change effects on groundwater quality

The availability of groundwater as a freshwater resource for human uses and ecosystem services depends on both its quantity and its quality. Most of section 5.5 focuses on the effect of climate change on groundwater quantity, but climate change and society’s response to it can also influence groundwater quality in several ways.

• Saltwater intrusion: A rise in sea level can increase the movement of saline seawater into aquifers along Canada’s coastlines, some of which have the highest projected rates of sea level rise in the world (James et al., 2021), and into aquifers in coastal islands (Stanic et al., 2024).
• Groundwater flooding: In coastal regions, a rise in sea level can cause not only higher groundwater levels, but also higher lake water levels, which in turn can lead to greater groundwater contamination when contaminant sources near the ground surface are inundated (flooded). For example, models for a rural community on the north shore of Nova Scotia (Threndyle et al., 2022) show that up to 9% of onsite wastewater septic systems are inundated under current conditions, but that inundation could reach 27% under the climate change scenario with the highest recharge and sea level rise.
• Urban runoff pollution: Modern stormwater and flooding management infrastructure (such as low impact development) tends to use natural features and green infrastructure, such as rain gardens and tree pits, to encourage groundwater recharge as a way of limiting runoff, but this also promotes the transport of contaminants associated with urban runoff (such as road salt, tire and brake wear chemicals and metals, lawn pesticides and fertilizers) to groundwater (Pitt et al., 1999).
• Road salt application: Changing winter temperatures, related changes from snowfall to rainfall amounts, and extreme weather events may alter national and regional patterns of road salt application and the related groundwater contamination, as noted for a region in Sweden (Arvidsson et al., 2012). This is a topic of major concern in Canada (Rudolph et al., 2023).
• Carbon capture and storage: One strategy to reduce greenhouse gas emissions is carbon capture and storage, which involves injecting carbon dioxide into deep geological formations for storage over geological timescales. There are several examples of active carbon capture and storage projects in Canada (e.g., Macquet et al., 2022). The potential upward migration of the carbon dioxide, through natural pathways or well failure, causes concerns about impaired groundwater quality with reduced pH and the subsequent release of hazardous metals (for example, Pb, Cd, As and U) (Zheng et al., 2021).
• Managed aquifer recharge: This water storage strategy involves intentionally recharging water into aquifers for later withdrawal and use, such as in times of summer dry periods or drought. However, the water used for recharge—surface water or treated wastewater—may carry pollutants, especially those not adequately removed by wastewater treatment, such as pharmaceuticals and per- and polyfluoroalkylated substances (also known as forever chemicals). While some can be attenuated in the managed aquifer recharge process, others may impair groundwater quality at the site (Yuan et al., 2016).
• Permafrost contaminants: The warming climate is leading to increasing permafrost thaw in northern landscapes (Chapter 6, section 6.7). This increasing permafrost thaw heightens the probability of contamination of the underlying groundwater, both through the release of naturally occurring or geogenic pollutants (such as carbon species or heavy metals) previously held in the permafrost and by opening contaminant transport pathways for surface-based sources (for example, landfills, legacy drilling sumps, wastewater lagoons, and leaky petroleum tanks) (McKenzie et al., 2021). This contamination of groundwater may threaten drinking water sources and alter the timing of contaminant transport to nearby surface waters.
• Land-use change: Finally, climate change may drive changes in land use (including the type and intensity of agriculture practiced) that could alter the types and amounts of contaminants entering an area’s groundwater (e.g., Persaud & Levison, 2021).

5.5.3: Confidence terms in key messages: summary of evidence

Key message 5.6: Groundwater recharge is anticipated to occur earlier in the year across the country, largely because of earlier snowmelt and more winter rain events (high confidence). The greatest changes in groundwater systems are expected to occur in northern Canada because of thawing permafrost, which may result in new groundwater pathways (medium confidence). This would allow more interaction between deeper groundwater and surface water systems with possible effects on surface water quality.

Key message 5.7: Groundwater is expected to remain one of the more resilient freshwater resources in a changing climate in comparison to surface water (medium confidence), given its naturally slow flow and enormous storage capacity, and if extraction through pumping does not markedly increase.

We have high confidence in an earlier onset of spring groundwater recharge due to snowmelt and the higher incidences of winter rain events. Our high confidence is based on several regional climate change studies that consistently show a seasonal shift in timing toward earlier recharge in association with projected earlier snowmelt. It is also consistent with the projection of earlier spring freshets (section 5.3) and the higher proportion of rain versus snow (section 5.2).

We have medium confidence that the effects of climate change on groundwater are expected to be greatest in northern Canada, where warming rates are highest, thus increasing permafrost thaw (Chapter 6, section 6.7) and groundwater interactions with bodies of surface water. Evidence of these changes in Canada’s northern watersheds is already being reported in the recently increasing number of publications on the subject. However, our confidence is restricted to medium given that future changes in other regions of Canada remain highly uncertain.

Our medium confidence in groundwater remaining one of the more resilient freshwater resources in a changing climate in comparison to surface water is based on the fact that groundwater fluctuations in response to climate tend to be much smaller than those observed in surface water systems. As a result, many large groundwater systems are in a constant state of disequilibrium with the current climate conditions (Rousseau-Gueutin et al., 2013). It has been shown that responses of most groundwater systems in Canada lag behind changes in climate, and the full impact of new and changing climate conditions on groundwater levels may not be fully realized for decades in much of Ontario and Quebec and for millennia in parts of the Prairies and Atlantic Canada (Cuthbert et al., 2019). This slow response of regional storage in the groundwater reservoirs to changes in climate demonstrates the resilient nature of the groundwater resource and illustrates the capacity of groundwater to mitigate climate impacts associated with surface water resources locally and regionally. However, the impact of human interventions in the groundwater system (extraction, increased irrigation, water management policy decisions, etc.) result in our medium confidence in this resiliency.

5.6: Droughts

Key message 5.8: Meteorological and agricultural droughts are projected to be longer and more frequent and intense across central and southern Canada during summer, and to be more prominent with higher amounts of global warming and at the end of the century (high confidence). Summer hydrological droughts are also projected to be longer and more frequent and intense in many regions of southern Canada, mainly because of increased evaporation and lower runoff from mountainous regions (low confidence). Historically, periodic droughts have occurred across much of Canada, but no long-term changes in their frequency are detectable (high confidence).

Drought is defined as a period of abnormally dry weather long enough to cause a serious hydrological imbalance (e.g., Seneviratne et al., 2012). Drought therefore has impacts on several components of the water cycle, including soil moisture and surface and subsurface water levels. These impacts can also be exacerbated by increases in evapotranspiration (ET) associated with high temperatures. This section assesses various types of droughts in Canada, including meteorological, agricultural, and hydrological droughts (Figure 5.17).

Droughts are complex climate-related hazards that affect a wide range of sectors of society, including food security, energy production, industry, forestry, recreation, aquatic ecosystems, and human health. Droughts are commonly characterized by their physical aspects (precipitation, soil moisture, water levels, etc.), while changes in drought are typically described in terms of changes in their frequency, severity, and duration. Impacts to human and natural systems from drought are referred to as drought risks, which take into consideration the exposure and vulnerability of those systems (Blauhut, 2020; Wilhite et al., 2014). This section focuses on past and future changes in droughts. Depending on their climate elements and associated affected systems, droughts may be classified into different types, including meteorological, agricultural, hydrological, ecological, and socio-economic (Figure 5.17). A lack of precipitation and a rise in temperature can lead to meteorological drought. This results in an increase in evaporative demand, which affects other aspects of the water cycle. These effects include decreased soil moisture leading to agricultural drought; water shortage in streams or storage locations, such as reservoirs, lakes, and groundwater, leading to hydrological drought; plant water stress that can lead to ecological drought; and socio-economic implications, such as health and food security (A. Berg & Sheffield, 2018; Van Loon, 2015). Droughts can also occur on a variety of timescales, ranging from a sudden and rapid onset of drought conditions over a short period of time, namely, weeks, called “flash droughts” (e.g., Hoell et al., 2020), to seasonal and annual droughts (e.g., Umphlett et al., 2023), and multi-year or decades-long droughts (e.g., Hanesiak et al., 2011), sometimes coined “megadroughts.”

Figure take-away: Imbalances between temperature and precipitation can trigger a cascade of droughts over time.

Figure 5.17: Diagram of meteorological, agricultural, hydrological, ecological, and socio-economic droughts. Most droughts are triggered by decreases in precipitation and increases in temperature and evapotranspiration. These are known as meteorological droughts. If these conditions persist, they can lead to other types of droughts and associated impacts, including agricultural droughts (decreased soil moisture and resulting declines in crop productivity), hydrological droughts (decreases in streamflow, surface water, and groundwater levels), ecological droughts (reduced water quality, and aquatic and ecological habitat destruction), and socio-economic droughts (impacts on society, including economic output and human health). The longer a drought lasts, the greater the impacts from all drought types.

5.6.1: Indices

Given its complex nature and wide-ranging impacts, drought cannot be characterized using a single universal definition (Lloyd-Hughes, 2014). Various indices can be used to quantify the duration, frequency, and intensity of a range of drought types. Generally, precipitation is a key variable when quantifying meteorological drought. The number of consecutive dry days or the length of dry spells is often used to characterize dry conditions. While this index can provide some insight into increased or abnormal drying in a region, it is more advantageous to use a standardized index that enables comparisons among different regions. One example is the Standardized Precipitation Index, which has been widely used for many meteorological drought studies. However, with past and projected human-caused climate warming across Canada (Zhang et al., 2019), there is a need to consider higher evaporative demand, which is not included in the Standardized Precipitation Index (Jeong et al., 2014).

 In a warmer climate, large increases in atmospheric evaporative demand, termed potential evapotranspiration (PET), may cause greater widespread drying (e.g., Zhao & Dai, 2015). When estimating PET, multiple elements influencing the evaporative process should be considered, including wind speed, humidity, radiation, and air temperature (McMahon et al., 2013). According to the Clausius-Clapeyron relationship, warmer temperatures lead to an increase in saturation water vapour pressure by about 7% per degree Celsius, and an increase in water-holding capacity increases the potential amount of evaporative demand (Chapter 8, Box 8.3) (Balting et al., 2021). Low precipitation can lead to a deficit in water availability, and an increase in ET due to warm temperatures can increase drying, including soil drying and plant stress (Douville et al., 2021). PET is subtracted from precipitation to formulate a metric of meteorological drought severity, such as the Palmer Drought Severity Index (PDSI) (Palmer, 1965) and the Standardized Precipitation Evapotranspiration Index (SPEI) (Beguería et al., 2014; Vicente-Serrano et al., 2010). ET is difficult to measure, and so it is typically estimated using various approaches. Estimates are also required when looking at projections. In estimating PET, physically based combination methods such as the Penman-Monteith equation are considered more accurate compared to those based solely on temperature and are recommended as the standard approach (McAfee, 2013; Pereira et al., 2015; Seneviratne et al., 2021; Sheffield et al., 2012).

Projections in meteorological drought indices are often used in combination with agricultural and hydrological drought projections partly because hydroclimatic responses to human-caused climate warming differ from region to region (Cook et al., 2020). Various hydrological variables (such as streamflow, surface water, and groundwater levels) can also be used to assess changes in freshwater availability (sections 5.3, 5.4, and 5.5). Many of these variables are obtained from hydrological models that use temperature and precipitation inputs from climate models. To assess hydrological droughts, scientists use indicators of water resource availability at the surface and subsurface level, such as standardized runoff, streamflow, and groundwater indices (Gosling et al., 2017; Seneviratne et al., 2021; Van Loon, 2015). For other variables, such as soil moisture, quantifying long-term trends may be challenging (Box 5.4). Nonetheless, soil moisture deficit, captured by indices such as a standardized soil moisture index or soil moisture anomalies, has been found to be an effective measure of agricultural drought (Berg & Sheffield, 2018; Bonsal et al., 2019; C. Champagne et al., 2019; Orlowsky & Seneviratne, 2013) and is relevant for measuring ecological droughts (Seneviratne et al., 2021). Soil moisture deficit is commonly used in conjunction with crop yield to measure related impacts of agricultural drought (Mardian et al., 2023, 2024; Masud et al., 2020; Quiring & Papakryiakou, 2003).

CCCR2019 based its assessment on several regional studies mainly focusing on drought projections across the Prairies (Bonsal et al., 2019). Since then, there have been a few Canada-wide drought projection studies, which are described in section 5.6.3. While several recent global drought studies cover North America, the focus in these sections is on studies that specifically look at Canada. Therefore, recent Canada-wide studies are assessed first, followed by regional studies and global studies where necessary.

Box 5.4: The challenge of quantifying long-term past and future soil moisture trends

Efforts to quantify soil moisture through ground measurements, models, or satellite observations are closely tied to efforts to quantify drought and its biophysical impacts, including forest fire risk assessment (Ambadan et al., 2020; Hanes et al., 2023), crop yield prediction (White et al., 2020), and flood prediction (Wadsworth et al., 2020). Direct measurements of soil moisture are sparse across Canada, so soil moisture is estimated primarily through modelling approaches (e.g., Sadri et al., 2022), with satellite data used to improve those estimates (Carrera et al., 2019). The lack of an extensive monitoring network and the relatively short length of time covered by most satellite data records make it difficult to conduct large-scale assessments of past trends (e.g., Bonsal et al., 2019; Mortsch et al., 2015). Future changes in soil moisture are primarily calculated using direct soil moisture projections from GCMs. These changes are influenced by future precipitation and evaporation, the latter of which may be affected by changes in vegetation. However, simulated soil moisture is associated with large uncertainties due to complexities in the representation of actual evapotranspiration, vegetation growth, and water use efficiency under higher atmospheric carbon dioxide concentrations (e.g., Hsu & Dirmeyer, 2023; Mankin et al., 2017; Wehner et al., 2017).

Quantifying soil moisture across large areas is challenging because of the variability of soil moisture over time and among regions (Famiglietti et al., 2008). Although Canada, unlike some countries, has no national mesonets (networks of weather stations), it does have several regional and provincial mesonets that collect measurements of soil moisture. For example, for the past 15 years, Alberta has monitored meteorological characteristics associated with drought, including soil moisture conditions, across a large network in the province (Agboma & Itenfisu, 2020), while Saskatchewan, Manitoba, and Ontario have established soil moisture and weather monitoring stations for selected regions to support the calibration and validation of models used to calculate soil moisture from satellite data (Adams et al., 2015; C. Champagne et al., 2016; Merzouki et al., 2019; Oozeer et al., 2020; Pacheco et al., 2015; Tetlock et al., 2019), as well as hydrological models (Sadri et al., 2022). Given the difficulties (including high costs) of direct soil moisture monitoring, numerous remote-sensing approaches have been used (Colliander et al., 2022; Kerr et al., 2012). In Canada, several soil moisture experiments have been conducted to improve satellite soil moisture modelling across agricultural areas (Colliander et al., 2019; Magagi et al., 2013; McNairn et al., 2015) and boreal forest (Ambadan et al., 2022; Berg et al., 2025). However, satellite sensors are primarily sensitive to soil moisture near the surface (the top few centimeters). Despite this challenge, surface soil moisture data have been used to improve the representation of hydrological fluxes in land surface models (Carrera et al., 2019; Husain et al., 2016).

The difficulties associated with measuring current and past soil moisture conditions present challenges for modelling future trends because the projected models contain multiple sources of uncertainty. For example, recent research has highlighted the complexity and uncertainty involved in estimating soil moisture changes under future climate scenarios. Among models, there is some agreement that soil moisture in North America is expected to decline despite localized and seasonal increases in precipitation, with surface layers showing more pronounced decreases in soil moisture than deeper layers (Cook et al., 2020). This pattern is consistent with simulations from CMIP5 models (Berg et al., 2017; Cook et al., 2015, 2018). This pattern is potentially driven by increases in surface evapotranspiration caused by higher temperatures and increased photosynthetic activity from plants that remove water from the soil. This increase in photosynthetic activity could be due to higher productivity because of increased carbon dioxide in the atmosphere, but also to a longer growing season resulting from earlier snowmelt and unfrozen soils (Mankin et al., 2017). The multiple factors driving these changes are not as well simulated or accounted for in land surface models, adding to the uncertainty in the conclusions (Hsu & Dirmeyer, 2023). Canadian studies have indicated an expected worsening of soil moisture deficits driven by potential evapotranspiration across the Canadian Prairies, with southern Alberta showing the largest relative decreases in soil moisture for the periods from 2011 to 2040, 2041 to 2070 and 2071 to 2100, compared to a baseline from 1981 to 2010, and with areas in northern Alberta and eastern Manitoba showing the lowest relative decrease in soil moisture (Chipanshi et al., 2022). The Prairie agricultural zone is the area expected to be impacted by the greatest water deficits, reaching 50 to 70% from 2071 to 2100 for intermediate (RCP4.5) and very high (RCP8.5) emissions scenarios, respectively (Chipanshi et al., 2022b). This decrease in soil moisture will have effects on soil and land surface processes, including less tree growth (McCollum & Ibáñez, 2020) and lower soil pH due to lower rates of weathering that add minerals to the soil (Houle et al., 2020).

Model outcomes can be significantly affected by the simplification or exclusion of major feedback mechanisms from vegetation and soil organisms in modelling approaches, such as the impacts of carbon dioxide fertilization on plant water use, changes in rooting depths in response to crop water stress, and soil physical asymmetry between infiltration and evaporation processes (Berg et al., 2017). Improved measurement and models of soil moisture will result in better soil moisture estimates under future climate conditions. For example, land surface processes and the associated effects on agricultural production have a high degree of uncertainty (Qian et al., 2019; Smith et al., 2020), and the trade-off between increases in plant growth and their effects on soil moisture needs to be better understood to be modelled accurately. Earth observation studies showing variability in land surface response over time and in different places have improved our understanding of the impacts of excess moisture and moisture deficits on crop growth (Champagne et al., 2019; Mardian et al., 2024; White et al., 2019). Quantifying the impact on soil moisture of factors like managed soil drainage (such as tile drains in agricultural fields) and other changes in land management will be important for understanding future climate impacts on soil moisture (Smith et al., 2019).

5.6.2: Past changes

As assessed in CCCR2019 (Bonsal et al., 2019), “periodic droughts have occurred across much of Canada, but no long-term changes are evident.” Since that assessment, a few major drought events have been documented across the country, but they have not influenced long-term trends. Of note, in the summer of 2021, a severe drought and extreme heat impacted a large area in much of western Canada and the United States (Philip et al., 2022; Thompson et al., 2022; Zhang et al., 2023). This event led to hundreds of deaths, devastating impacts on marine life and agriculture yield, wildfires that subsequently led to landslides, and river flooding from snow and glacier melt (Niggli et al., 2022; White et al., 2023). Dry-spell trends across Canada from 1979 to 2018 showed that the southern Canadian Prairies experienced an increase in the number and duration of these events (Yang et al., 2020). Similarly, analysis of meteorological droughts across Canada from 1950 to 2013, using the SPEI, revealed that the continental interior of Canada, and most noticeably the southern Prairies, experienced an increase in moisture deficit (Asong et al., 2018). However, the analysis also determined that there was considerable drought variability over these years in the Prairies, leading to no discernable long-term trends, a result that is in line with those of other past studies (e.g., Bonsal et al., 2011, 2017; Wang et al., 2014). In addition, the study identified a tendency for drought to recur at a frequency of every 8 to 32 months in the Prairie region and every 8 to 40 months in north-central Canada, frequencies that were likely influenced by large-scale atmosphere-ocean modes of internal climate variability such as the El Niño–Southern Oscillation and the Pacific–North American teleconnection pattern (Chapter 4, section 4.8) (Asong et al., 2018).

5.6.3: Future changes

5.6.3.1: Meteorological drought

Parts of Canada are projected to experience an increase in the frequency and severity of meteorological droughts in a changing climate. Nationwide, SPEI projections (using the Penman Monteith method for PET) from 22 CMIP6 GCMs show a progressive increase in annual drying over the century, particularly across central and southern Canada, including interior British Columbia. This drying is more pronounced for high (SSP3-7.0) and very high (SSP5-8.5) emission scenarios (Bonsal et al., 2024). An increase in summer (June-July-August) drying is projected across much of Canada, with the driest SPEI values in southern and central regions of Canada under a very high emissions scenario by late century (Tam et al., 2023). According to the same very high emissions scenario, a projected increase in spring drying in the northwestern region of Canada is projected by late-century (2081–2100) (Tam et al., 2023). Similarly, Canada-wide CMIP5 multi-model SPEI projections from 29 GCMs show that meteorological drought events are projected to be longer and more frequent and intense under high and very high emissions scenarios in Canadian regions, including southwestern and central Canada, during the warm seasons by the end of the century (Stewart et al., 2019; Tam et al., 2019, 2023). Regional studies show similar results, where the Canadian Prairies in particular are projected to experience an increase in the duration and intensity of severe droughts (Bonsal et al., 2020; Mousavi et al., 2024). They are also projected to experience a decrease in the growth and retreat periods of drought events, meaning that droughts will develop more rapidly and end more suddenly toward the end of the century under high and very high emissions scenarios (Bonsal et al., 2020). According to an RCM ensemble, researchers found similar results where PDSI and SPEI projections suggest an increase in drought duration and severity across the southern part of the Canadian Prairies under various global warming levels (1.5–3°C) (Zare et al., 2023). For all these studies, droughts were projected to be longer and more frequent and intense with higher amounts of global warming and at the end of the century.

Additional evidence for the increased frequency in extreme meteorological droughts was provided in an assessment of 22 CMIP6 SPEI projections using the Penman-Monteith method to calculate PET. Specifically, drought events occurring once every 10 years were projected to occur more frequently across the interior continental region of Canada, especially the Canadian Prairies and northern Ontario under a warming climate. Under a very high emissions scenario (SSP5-8.5), this once-in-a-decade event increases to 3 to 4 occurrences every 10 years for the mid-century (2041–2060), and to 6 to 8 occurrences every 10 years for the late century (2081–2100) (Figure 5.18a,b) (Bonsal et al., 2024). In addition, most drought increases are projected across the southern half of the Canadian Prairies, with much of this region expected to experience 8 to 10 more years of severe drought (SPEI < -1.5) and 4 to 6 more years of extreme drought (SPEI < -2.0) in the late century under a very high emissions scenario. Low (SSP1-2.6) and intermediate (SSP2-4.5) emissions scenarios show increases in the southern Prairies of 2 to 3 and 3 to 5 occurrences, respectively, every 10 years for the late century. Seasonally, projections indicate that there may be more frequent severe and extreme summer droughts across most of Canada, especially across the southern half of the country under a very high emissions scenario by late-century (Tam et al., 2023).

Global and North American CMIP5 studies show similar results. Drought projections under high and very high emissions scenarios reveal an increase in the frequency of late-century severe to extreme drought conditions across much of southern Canada, including southeast British Columbia, the Prairies and Ontario, as measured by PDSI, SPEI, and soil moisture (Dai, 2013; Dibike et al., 2017). Under high and very high emissions scenarios, projected changes in climate in Canada are anticipated to result in longer, more severe and extreme meteorological droughts, particularly in southern interior locations such as the Canadian Prairies.

5.6.3.2: Agricultural drought

Areas across Canada are expected to experience an increase in agricultural drought (soil moisture deficit) under human-caused climate warming (Box 5.4). Nationwide projections based on 22 CMIP6 standardized simulations of total soil moisture reveal that the frequency of extreme agricultural droughts will increase across most of Canada for all emissions scenarios (Figure 5.18) (Bonsal et al., 2024). Several regional studies of the Prairies show similar results. RCM Soil Moisture Deficit Index ensemble projections show that an increase in the frequency of drought under a global warming level of 3°C (close to an intermediate emissions scenario in terms of end-of-century warming) is projected across the southern Canadian Prairies (Zare et al., 2023). Similarly, results based on CMIP5 GCMs show that there will be greater moisture deficits as represented by four agroclimatic indices (Effective Growing Degree Days, Growing Season Length, Climate Moisture Index, and Temperature Humidity Index), across the Canadian Prairies under higher emissions scenarios by 2071 to 2100. The severity of moisture deficits is driven by PET across the Canadian Prairies, with southern Alberta showing the largest relative decreases in soil moisture (Chipanshi et al., 2022a).

Despite projected increases in precipitation, a global CMIP5 study found that regions in North America, including Canada, may see a longer and more frequent meteorological and soil moisture droughts under global warming levels of 1.5°C and 2°C (Xu et al., 2019). This finding corroborates other studies that project large-scale surface and total soil moisture drying across North America using both CMIP5 and CMIP6 projections (Berg et al., 2017; Cook et al., 2020; Zhao & Dai, 2021).

5.6.3.3: Hydrological drought

Depending on the type of hydrological drought, certain regions in Canada are projected to experience an increase in drought frequency and severity. For example, under low, intermediate, and especially very high emissions scenarios, nationwide projections based on 17 CMIP6 standardized surface runoff simulations show that warm-season extreme droughts will be more frequent by the end of the century across most regions of Canada (Figure 5.18b) (Bonsal et al., 2024). While some of Canada may see decreased runoff, other parts such as the northern latitudes, may see an increase in wetter conditions (Bonsal et al., 2024; Vieira & Stadnyk, 2023).

Figure take-away: Once-in-a-decade droughts are projected to increase in frequency in the mid-century (2041–2060) and late-century (2081–2100) across many areas of Canada.

Figure 5.18: Maps of projected changes in once-in-a-decade warm-season (April–September) occurrences of drought under different emissions scenarios and for a) 2041 to 2060 and b) 2081 to 2100, based on 22 projections from the CMIP6 global climate models. Each row shows, for a particular drought index, how climate change influences the frequency of extreme drought events. Each column shows the projected changes for a given emissions scenario. Specifically, the projections are based on low (SSP1-2.6) (left column), intermediate (SSP2-4.5) (middle column), and very high (SSP5-8.5) (right column) emissions scenarios for the Standardized Precipitation Evapotranspiration Index (SPEI) (meteorological drought) (first and fourth row), total soil moisture (agricultural drought) (second and fifth row), and surface runoff (hydrological drought) (third and sixth row). Source: Bonsal et al. (2024).

Declines in snow cover (Chapter 6, section 6.2) can result in another type of hydrological drought, namely, snow droughts. Often defined as snow water equivalent deficits or more simply a lack of snow accumulation, snow droughts are not as extensively researched compared to other types of droughts (Dierauer et al., 2019; Harpold et al., 2017; Huning & AghaKouchak, 2020). Nonetheless, these types of droughts can lead to water deficits in other aspects of the ecosystem (such as soil moisture) in spring and summer. They also have significant ecological and socio-economic consequences, such as impacts on water storage and availability and on aquatic ecosystems. Regional studies show that western Canada may experience an increase in snow droughts under various scenarios of future climate change (Dierauer et al., 2021; Huang et al., 2024;  Shrestha, Bonsal, Bonnyman , et al., 2021). According to a CMIP5 RCM ensemble, regions in western Canada covering the four major tributaries of the Mackenzie River (the Peel, Liard, Peace, and Athabasca river basins), along with the Yukon, Skeena, Saskatchewan, Fraser, and Columbia river basins, are projected to experience increasingly larger declines in snowpack storage, resulting in snow droughts as global warming levels increase from 1.0 to 4.0°C (Shrestha, Bonsal, Bonnyman, et al., 2021). Across a watershed in Saskatchewan, CMIP6 projections show that increases in snow droughts under both low (SSP1-2.6) and very high (SSP5-8.5) emissions scenarios may affect other water availability deficits, including groundwater (Huang et al., 2024).

The quantification of mountainous snowpacks is often used to predict seasonal streamflow water availability in subsequent seasons, although in a changing climate the reliability of predictions declines (Livneh & Badger, 2020). Still, projections show that a decline in snowpack may result in below-normal summer streamflow, often called streamflow drought. Using one-month standardized streamflow projections from two CMIP5 large GCM ensembles based on a high emissions scenario (SSP3-7.0), researchers projected that hydrological droughts currently occurring once every 2 years and once every 100 years will increase in occurrence, except for some watersheds in western Canada, by the end of the century (Zhao et al., 2020). A regional study of four catchments in British Columbia found that snow droughts may become more frequent and severe under high and very high emissions scenarios by the 2050s and 2080s, leading to decreased summer streamflow and groundwater storage and more severe and prolonged summer low flow periods (Berthot et al., 2021; Dierauer et al., 2021).

5.6.4: Confidence terms in key messages: summary of evidence

Key message 5.8: Meteorological and agricultural droughts are projected to be longer and more frequent and intense across central and southern Canada during summer, and to be more prominent with higher amounts of global warming and at the end of the century (high confidence). Summer hydrological droughts are also projected to be longer and more frequent and intense in many regions of southern Canada, mainly because of increased evaporation and lower runoff from mountainous regions (low confidence). Historically, periodic droughts have occurred across much of Canada, but no long-term changes in their frequency are detectable (high confidence).

Different kinds of droughts are defined in this chapter in section 5.6.1 and Figure 5.17. For future meteorological and agricultural droughts, our high confidence assessment is based on the high level of agreement among recent nationwide and regional studies, which project longer and more frequent and intense droughts across central and southern Canada, particularly during the warmer season (such as summer) with higher amounts of global warming and in the late century (Figure 5.18). This is consistent with several global-scale drought studies that primarily show increased drought potential in summer across continental interior regions (including interior British Columbia and the southern Prairies). It is also consistent with CCCR2019. In addition, since CCCR2019 was released, researchers have conducted several Canada-wide meteorological drought studies where SPEI was calculated using the physically based Penman-Monteith method, which is more accurate than previous studies that only incorporated temperature, thus adding to our level of confidence.

Regarding the second statement, evidence indicates that summer hydrological droughts will become more frequent and intense in many regions of southern Canada, particularly those located in mountainous and downstream mountainous regions. This is mainly due to decreased snow accumulation (called “snow droughts”) and resulting lower runoff in the ensuing summer. In addition, evaporation is expected to increase because of warmer temperatures and longer ice-free periods (section 5.4). Our level of confidence is low since these results are based on only a few nationwide and regional studies, the latter of which are fragmented across Canada.

Regarding the third statement, there is a high level of agreement among many nationwide and regional studies using several different drought-related indices that past occurrences of drought are dominated by considerable variability. Many of these studies have been published since the release of CCCR2019 and are consistent with the findings of CCCR2019, thus warranting the high confidence assessment.

5.7: Floods

Key message 5.9: Over the period of observation, there have been no consistent trends in streamflow flood events across the country (high confidence). Streamflow-related floods in Canada are driven by multiple factors, including extreme precipitation, rapid snowmelt, rain-on-snow events, and ice jams, with complex interactions among these drivers.

Key message 5.10: Projected increases in extreme precipitation are expected to lead to more frequent and intense flash flooding across Canada (high confidence). Warmer temperatures are expected to lead to the earlier occurrence of snowmelt, rain-on-snow events, and ice jam breakups, resulting in earlier streamflow-related spring floods (medium confidence). However, their future frequency remains uncertain because of the interactions among rising temperatures, reduced snow cover, and the complex dynamics of ice jam–related and snowmelt-related floods. 

Flooding is a frequent and costly natural hazard in Canada, leading to extensive infrastructure and property damage and substantial government expenditures for disaster assistance (Box 5.5) (Henstra et al., 2019; Mohanty and Simonovic, 2021; Oulahen, 2015). Seven of Canada’s ten most expensive floods from 1980 to 2019 occurred after 2010, reflecting higher flood-related risks due to both greater exposure of valuable assets and populations and potential changes in the frequency and intensity of flooding events. There are several types of floods, including streamflow (fluvial), rainfall-induced (pluvial), groundwater (caused by rising aquifer levels after prolonged precipitation or snowmelt), and coastal floods. This section primarily assesses streamflow-related floods, including those caused by extreme precipitation (flash floods), rapid snowmelt, rain-on-snow (ROS) events, and ice jams, as well as their implications for urban flooding. While this section provides an overview of how extreme precipitation influences streamflow flooding, detailed assessments of extreme precipitation patterns and their broader impacts are included in Chapter 8, section 8.3.

Snowmelt and ROS events play significant roles in triggering or exacerbating floods, particularly in snow-dominated regions, such as mountains, the Prairies, northern Ontario, and parts of central and eastern Canada. These events typically occur during spring freshet or mid-winter warm spells, when rising temperatures or rainfall rapidly release water from snowpacks, generating high levels of runoff over frozen or saturated soils. Floods in southcentral Canada, such as parts of southern Ontario and southern Manitoba, are often caused by prolonged storms or intense, short-duration rainfall events, sometimes compounded by ROS events during late winter or early spring. In contrast, floods in eastern Canada, including the Atlantic provinces, are typically triggered by heavy precipitation associated with extratropical cyclones or remnants of hurricanes, though ROS and snowmelt can also contribute to spring flooding in inland basins, such as the Saint John River (Milrad et al., 2009; Watt et al., 1989). The mountainous coastal areas of western Canada experience intense storms often fueled by atmospheric rivers (Chapter 4, section 4.5). These storms bring large amounts of moisture, and as the air is forced up the mountains, it cools and releases heavy rainfall, which can lead to significant flooding (Dettinger, 2011; Spry et al., 2014). Ice jams pose a significant risk by raising water levels upstream, leading to the overflow of riverbanks and flooding in adjacent low-lying areas. Furthermore, mid-winter breakup events, driven by rising temperatures or increased river flow, can lead to significant flooding downstream as ice fragments mobilize, increasing flow rates and water levels. When combined with heavy rainfall, the probability of downstream flooding is further heightened.

Urban flooding is another major source of disaster-related losses, not only affecting properties and infrastructure but also causing substantial social, economic, and health impacts. This type of flooding is generally triggered by heavy rainfall, which can be compounded by snowmelt and fluvial flooding, resulting in rapid surface runoff that overwhelms the capacity of urban drainage systems. Urban areas such as Toronto are particularly vulnerable to flash flooding because of aging infrastructure and the widespread presence of impervious surfaces such as buildings, roads and paved areas, which limit infiltration and increase surface runoff (Buttle et al., 2016; Feng et al., 2021). A warming atmosphere increases the potential for more intense and frequent extreme precipitation events. Warmer air can hold approximately 7% more moisture per 1°C increase in temperature, fueling heavier rainfall and contributing to an intensified hydrologic cycle (Chapter 8, Box 8.3). When combined with urban factors such as impervious surfaces and outdated drainage systems, these extreme precipitation events significantly increase the probability of urban flooding (Douville et al., 2021; Masud et al., 2017; Oh & Sushama, 2020; Radić et al., 2015; Westra et al., 2014; Zhang & Fueglistaler, 2019). Additionally, in Chapter 11 of IPCC AR6, WGII concludes with medium confidence that urbanization can intensify extreme precipitation over and downwind of cities, thereby exacerbating the chance of flooding (Seneviratne et al., 2021). Projected increases in extreme rainfall across Canada are expected to further increase the frequency and intensity of flash flooding, particularly in urban environments. Furthermore, the threat of coastal flooding is heightened by rising sea level and the potential for intensified storm surges, which pose risks to both the east and west coasts of Canada (ECCC, 2016; Golnaraghi et al., 2020; IPCC, 2022b; Jalili Pirani & Najafi, 2020, 2022, 2023a, 2023b) (Chapter 7, section 7.5). Storm surges, driven by strong winds and low-pressure systems during storms, are exacerbated by rising sea level and stronger storms fueled by warmer oceans and increased atmospheric moisture.

Growing evidence indicates that human-induced climate change, driven by greenhouse gas emissions, is increasingly influencing the occurrence of flooding. Studies on the causes have linked recent flood events to anthropogenic (human-caused) climate warming. For example, flooding in the Ottawa River Basin in 2017 and 2019 was driven by snowmelt and heavy rainfall on saturated and frozen soils. In 2019, the flood was caused by several days of heavy rain on an already above-average snowpack, with limited infiltration due to frozen ground. Analysis of the causes showed that anthropogenic forcing increased the likelihood of a 30-day high rainfall period by a factor of two to three (Kirchmeier-Young et al., 2021; Teufel et al., 2019). Similarly, the 2021 atmospheric river events in British Columbia showed a strong anthropogenic element, which contributed to the severity of the flooding, landslides, and infrastructure failures. These findings are consistent with projections of more frequent extreme events and substantial changes in snow dynamics, both of which are key contributors to the chance of flooding. Considering these challenges, recent assessments have highlighted the need to enhance environmental prediction systems in Canada by integrating diverse scientific disciplines, such as hydrology, climatology, and ecology, and strengthening collaboration among academia, government agencies, First Nations, Inuit, and Métis, and private-sector stakeholders. These efforts support a more unified approach to data sharing, policy development, and response strategies, to better manage water-related risks (Clark et al., 2023). Recent findings also emphasize the importance of incorporating the variability associated with future climate conditions into flood projections to improve the reliability of peak flow estimates.

Since the discontinuation of the Federal Flood Damage Reduction Program in 1999, flood management has become fragmented, leading to inconsistent and outdated flood mapping. Recent efforts include the development of the Federal Flood Mapping Guideline Series and updated hydrologic procedures to improve flood hazard assessments and incorporate climate change impacts. The Flood Hazard Identification and Mapping Program, a Canadian initiative led by Natural Resources Canada, contributes to this goal by integrating climate-informed modelling approaches that reflect changing conditions and better assess flood risks (Stadnyk & van der Eerden, 2024). Read more about flood management in Canada in Box 4.1 of the Water Resources chapter of the National Issues Report, a report contributing to the Canada in a Changing Climate: National Assessment Process.

Box 5.5: Climate change and flooding: implications for homeowner’s insurance

Although there is considerable uncertainty regarding how climate change will impact spring flooding driven by snowmelt, there is greater confidence that flash flooding associated with heavy-precipitation events will become more frequent (section 5.7). This will put additional pressure on Canadian homeowners’ insurability of flooding, whether the flood is due to a river overflowing or a sewer backup.

Flooding is not covered by basic homeowner’s insurance, but coverage is likely available if you purchase extra insurance. For a flood claim to be covered, the homeowner requires flood endorsement or comprehensive water coverage, both of which are considered extras (Insurance Bureau of Canada, 2025c). Availability of coverage also greatly depends on the type of flood. When there is heavy rain and the sewer system is overwhelmed, you need to make sure that sewer backup is included in the flood endorsement. But when a river overflows and floods a basement, overland flooding also needs to be included in the flood endorsement because not all types of flooding are covered similarly. Homeowners living on floodplains should also be aware that flood insurance typically excludes flooding caused by overflowing rivers. In this specific case, disaster victims may have other resources available (Insurance Bureau of Canada, 2025c; Public Safety Canada, 2022).

Provinces and territories offer disaster financial assistance to disaster victims for non-insurable events, such as overflowing rivers. This would typically be the main resource for homeowners residing in floodplain areas. It is important to emphasize that coverage is different from one province or territory to the next, and some provinces, namely, Quebec, New Brunswick and Alberta, limit financial assistance over time for repeated flooding. Once a homeowner no longer has access to private flood insurance or public financial assistance, then they are on their own, with potential consequences to their mortgages. This risk is real. For example, some homeowners in Quebec have recently faced difficulties renewing their mortgage since their financial institution required more equity for a home located on floodplains (Alberta Disaster Financial Assistance Program, 2025; Government of Quebec, 2025; Lecavalier, 2024; New Brunswick Disaster Financial Assistance Program, 2025; Public Safety Canada, 2022). In addition, the federal government does not directly help disaster victims but partly reimburses eligible expenses incurred by provinces and territories as part of their disaster financial assistance programs through what is known as the Disaster Financial Assistance Arrangements (Public Safety Canada, 2022, 2025)

It is important to emphasize that insurability of flooding also depends on the ability of the federal, provincial, territorial, and municipal governments and homeowners to reduce the vulnerability of homes to flooding. Improving and maintaining flood maps and regulations to avoid building on floodplains, updating infrastructure and building codes, and leveraging nature-based solutions are examples of measures that governments can take to reduce Canada’s vulnerability to flooding now and in the future. Coordination between these stakeholders is key for climate adaptation but is challenging (Insurance Bureau of Canada, 2025a, 2025b; Public Safety Canada, 2022).

Without proper investments in risk reduction, the viability of insurance programs is at stake, potentially leaving many Canadian communities without financial resources to recover from flooding. When homeowners are left without sufficient financial assistance, which is known as the insurance gap, the ability to get a mortgage on a home is more difficult, requiring more equity to purchase a house, restricting the pool of buyers, and potentially pushing the price of houses down. Addressing insurability to flooding (and other climate-related hazards) is key to improving resilience to climate change for people living in Canada.

5.7.1: Past changes

The first edition of this report, CCCR2019, highlighted regional variability in high-streamflow events, with some regions experiencing increases in frequency and magnitude, while others observed decreases (Bonsal et al., 2019). Flood events have become more frequent and intense over the past 30 to 40 years in parts of Atlantic, central, Prairie, and northern Canada, according to trends in the highest streamflow levels recorded each year (annual maximum) and other extreme streamflow events that surpassed defined thresholds (Mostofi Zadeh et al., 2020). However, caution is advised when interpreting these trends in historical streamflow records, because streamflow indicators can be sensitive to the specific period examined. Depending on whether shorter or longer time frames are used, the trends observed could even appear to be in the opposite direction. Trends in extreme precipitation exhibit regional variability across Canada, with some studies suggesting links between increased extreme rainfall and human influence (Kirchmeier-Young et al., 2021; Teufel et al., 2017, 2019). Most streams in Canada have experienced shifts in flow patterns, driven by simultaneous changes in streamflow characteristics, such as timing and magnitude (Zaerpour et al., 2021; section 5.3). A warming trend affects snow-dominated systems by reducing winter snow accumulation and altering how snowpack contributes to streamflow. In particular, nival (snowmelt-dominated) systems are experiencing earlier flood events, likely due to reduced snowpack, shifts in melt timing, and the greater potential for ROS events (Derksen et al., 2019). In spring, earlier and more rapid melting of a reduced snowpack alters the timing and dynamics of runoff generation. While smaller snowpack volumes may reduce the potential for prolonged flooding in some regions, accelerated melt rate, particularly when combined with saturated or frozen soils, can still produce high levels of runoff and increase the chance of flooding. As a result, snowmelt-driven flood events may occur more abruptly. Still, no clear trend in the frequency of annual high-flow events has emerged across regions. For example, certain snowmelt-dominated hydro-regions, such as the Pacific Northwest and the Rocky Mountain highlands, have shown an increase in the frequency of high-flow events (Dethier et al., 2020). This increase might be due to past increases in extreme precipitation during the high-flow season, which could offset the decrease in snowpack storage.

The extensive geographic variation in Canada leads to the diverse nature of flood dynamics. In Alberta, for example, although some trends, such as higher winter flows and earlier peak events, remain consistent, variations within individual basins show the nuanced nature of flood behaviour changes in the region. For instance, in the Peyto Glacier Basin, peak flows have transitioned from August to July, with glacier melt now contributing 43 to 59% of the total annual streamflow, compared to a wider historical range of 27 to 61% (Pradhananga & Pomeroy, 2022). In the Athabasca River Basin, peak flow magnitudes generally decreased after 1958 in the upper Athabasca River and the lower Athabasca River’s southern regions (Peters et al., 2022). A study examining 84 hydrometric stations in Canada’s permafrost region from 1976 to 2005 showed few significant trends in extreme streamflow parameters (Shrestha, Pesklevits,  et al., 2021). Only a small percentage of stations exhibited trends in the timing of maximum discharge rates, with changes of less than 15%, and even fewer displayed statistically significant trends.

Overall, the past trends in flooding across Canada exhibit substantial regional variability, with changes in high-flow frequency and magnitude linked to shifts in snowpack dynamics, temperature increases, ROS events, and extreme precipitation. While some regions show clear increases in high-flow events, other areas remain unchanged, and uncertainties persist because trends appear different, depending on the study period.

With respect to urban flooding, Sandink and Binns (2021) identified 21 major urban flood events from 2005 to 2020 across the country, with the most damaging occurring in the Greater Toronto Area in 2005 and 2013, resulting in insured losses of Can$795 million and Can$1.024 billion (in 2019 Canadian dollars), respectively. However, despite the frequency and severity of these events, long-term observational studies on urban flood trends in Canada are not currently available.

5.7.2: Future changes

CCCR2019 (Bonsal et al., 2019) emphasized the multifaceted nature of streamflow-related flooding in Canada. Building on that assessment, this section explores recent advances in understanding future flood dynamics in Canada, focusing on three main drivers: snowmelt, precipitation, and ice dynamics.

With ongoing climate warming, earlier snowmelt is projected across North America (IPCC, 2021). The implications of this change include intensified snowmelt-induced floods and increased ice movements in Canadian rivers (Burn & Whitfield, 2016). While warmer temperatures lead to earlier snowmelt and subsequent shorter durations of snow cover, they also contribute to more frequent mid-winter rains falling on snowpacks, exacerbating runoff and flooding, particularly at mid-to-high latitudes (e.g., Jeong & Sushama, 2018a). At lower elevations and latitudes, reduced snowpack and earlier snowmelt can decrease spring freshets, lowering their contribution to peak flows. Conversely, higher elevations, where snow cover persists, are projected to experience more ROS events, driven by shifts from snowfall to rainfall, increasing streamflow-related flooding in these areas (Musselman et al., 2018). The role of snow and snowmelt in peak flows and streamflow-related floods in Canada undergoes significant changes with climate variations. Decreases in extreme snow accumulation, measured as snow water equivalent, that is, the amount of water contained within the snowpack, have been projected alongside increases in extreme snowmelt and runoff potential, particularly in high-latitude areas, under warming temperatures (Cho et al., 2021). Similarly, decreases in snow cover area are anticipated (Siemens et al., 2021) (Chapter 6, section 6.2), contributing to altered river flow patterns, including decreased summer flows and earlier freshets. These changes highlight the complex interplay between latitude, elevation, and snowmelt dynamics in shaping future flood occurrences in Canada (Bonsal et al., 2020; Dibike et al., 2018).

Projections derived from CMIP6 simulations indicate increases in daily precipitation across Canada, particularly during the winter, spring, and fall (Pierce et al., 2023). Increased daily precipitation can contribute to higher flood risks, especially when thresholds for runoff or drainage capacity are exceeded. ROS events are projected to increase north of the 0°C air temperature isotherm and at higher elevations, where snow cover persists, while decreasing below the 0°C isotherm and at lower elevations because of reduced snowpack and more frequent winter rainfall (Jeong & Sushama, 2018b). This projection is consistent with the most recent IPCC assessment (IPCC, 2022b), which indicates that ROS-induced floods in Canada are expected to become more frequent at higher elevations and less frequent at lower elevations. CCCR2019 (Bonsal et al., 2019) also projected increases in ROS events from November to March across most Canadian regions, driven by warmer air temperatures and more frequent rainfall events (Jeong & Sushama, 2018; Musselman et al., 2018). Recent large ensemble simulations project that the peak ROS season may shift to earlier, particularly to early winter in high-elevation regions, and that the contribution of ROS events to heavy runoff will decline at higher warming levels. This projection is consistent with spatial patterns identified in other studies, with the decline especially evident in the Great Lakes, eastern Canada, and parts of the Pacific Northwest. In high-latitude areas, increased ROS frequency in fall and early winter, combined with higher levels of runoff, is likely to increase the chance of flooding. In contrast, ROS may occur less in spring at lower elevations because of snowpack losses (Warden et al., 2024).

Warmer temperatures can lead to earlier and more frequent ice breakups and increased ice movements in Canadian rivers. Climate change is projected to result in fewer and shorter cold spells across Canada, while contributing to more frequent and prolonged mid-winter and early spring ice-melting conditions (Chapter 8, section 8.2). These changes are expected to result in thinner river ice, reduced maximum winter ice thickness, and earlier ice breakups (Chapter 6, section 6.4). For example, under a very high emissions scenario, average ice thickness in the Peace River is expected to decrease by about 0.2 m from the 1980s to the 2050s. The interplay of earlier and thinner ice with mid-winter warming conditions could reduce the frequency of ice jam floods in some regions. However, thinner ice and thermal breakups can result in more unpredictable ice movements, potentially shifting the timing and locations of ice jam formation and increasing the chances of mid-winter flooding in high-latitude or northern regions. In the delta reach of the lower Peace River, less frequent but unpredictable ice jam floods could impact water resources and ecosystems dependent on flood dynamics (Beltaos & Bonsal, 2021).

Overall, changes in snowmelt, precipitation, and ice dynamics are projected to alter flood patterns across Canada. Earlier snowmelt, more frequent ROS events at higher latitudes, and shifting ice conditions can increase the chances of flooding, particularly in northern and high-elevation regions. Additionally, the frequency of high-flow events is increasing in areas where rainfall is a dominant factor. While there is high confidence that increases in extreme precipitation will heighten the probability of urban flooding, the interaction of reduced snow cover, earlier spring freshets, and more frequent ROS events introduces substantial regional variability in the chance of flooding. Projected decreases in snow cover and earlier ice breakup in Canadian rivers further suggest a higher likelihood of mid-winter floods. Smaller watersheds, which respond rapidly to intense rainfall, may also be particularly sensitive to changes in the frequency or intensity of localized extreme precipitation, potentially increasing the chance of flash flooding in some regions.

These evolving flood dynamics illustrate the importance of understanding the interconnected drivers of urban and riverine flooding under changing climate conditions. A summary of the projected changes in key flood drivers in Canada under a changing climate appears in Figure 5.19.

Figure take-away: Flooding in Canada is complex. Climate warming impacts several drivers of flood conditions, which can then cause changes in future flood timing and frequency.

Figure 5.19: Diagram of assessed changes in flood drivers, flood occurrence, and flood timing. The confidence levels (high or medium) are in line with findings discussed in section 5.2 on the atmospheric component of the water cycle, in Chapter 8 on precipitation extremes, and in Chapter 6 on snow and ice dynamics.

5.7.3: Shifts in regional flooding under climate change

Despite the substantial regional variability in flood patterns, the common theme emerging across Canada is that multiple flood drivers can interact to increase the chances of flooding. For example, in the Canadian Prairies, rapid snowmelt combined with extreme rainfall triggered the 2013 Alberta floods, which shows how multiple flood drivers can interact (Pomeroy et al., 2016). Similarly, the 2011 flood in the Red and Souris river basins was driven by a combination of high prior soil moisture, deep frost, above-average snowpack, and, particularly in the Souris region, substantial spring rainfall, which together overwhelmed infiltration capacity and amplified runoff (Stadnyk et al., 2016). In contrast, the 2014 Assiniboine River flood was Manitoba’s first major rainfall-induced summer flood, occurring after the spring freshet. It caused extensive damages and infrastructure failures because unfrozen dikes were overtopped during intense late June rainfall (Ahmari et al., 2016). More recently, the 2021 atmospheric river event in British Columbia resulted in severe flooding, landslides, and infrastructure disruptions, illustrating the growing risks of extreme precipitation and compounding events (Gillett et al., 2022). Higher chances of extreme precipitation events, particularly in western Canada and on the Atlantic coast, further exacerbate flood risks in these regions (Dibike et al., 2021; Jalili Pirani & Najafi, 2020). Additionally, various regions show altered hydrological patterns, characterized by changes in streamflow timing and flood levels, indicative of the influence of climate change on hydrological processes (Dietrich, 2019; Islam, Curry, et al., 2019). Accelerated snowmelt and earlier peak flows are also widespread, impacting in particular Alberta and high-latitude regions (Pradhananga & Pomeroy, 2022; Shrestha, Pesklevits, , et al., 2021). A summary of key regional flooding characteristics is presented in Table 1 below, followed by a detailed discussion for each region.

Table 5.1: Summary of past and future changes in flooding characteristics across regions of Canada

This table summarizes consistent findings from the literature assessed. No formal assessment of confidence was done on these regional changes.

5.7.3.1: Western Canada

Flood patterns in western Canada are projected to shift under climate change because of increases in annual maximum flows, more frequent extreme precipitation events, and changes in the timing of snowmelt and runoff. Across much of the region, projections indicate earlier peak flows, increased winter and spring flow rates, and higher chances of flooding, particularly in response to more extreme precipitation and changes in seasonal snowmelt dynamics (Dibike et al., 2021; Krogh & Pomeroy, 2019; Siemens et al., 2021). For instance, increased cold-season rainfall is expected to contribute to a transition in regions such as the Fraser River Basin to a mixed nival-pluvial (snowmelt- and rainfall-dominated) regime, where extreme rainfall events drive peak daily flows. Similarly, studies project higher winter flows and earlier peak runoff timing in basins such as the Athabasca and Saskatchewan river basins, driven by warmer temperatures and changing precipitation patterns (Ammar et al., 2020; Dibike et al., 2021; Islam, Curry, et al., 2019).

While regional variability exists, some studies suggest a higher likelihood of more frequent extreme flow events and lower summer and fall flows in many watersheds (Chegwidden et al., 2019). These findings highlight the role of extreme precipitation and snowmelt in driving flood risks and underscore the need to understand how shifting hydrological patterns may affect flood hazards.

5.7.3.2: Northern Canada

Flood projections for high-latitude regions indicate complex and variable responses to climate change. Projections suggest increases in annual flows, earlier peak flows, and higher chances of intense peak flow events driven by changing precipitation patterns and snowmelt dynamics (Nolin et al., 2023;. Shrestha et al., 2019). In sub-Arctic river basins, such as the Upper Harricana River, more-frequent and higher-magnitude spring discharge events are anticipated because of altered precipitation and thawing permafrost (Nolin et al., 2023). Similarly, in northwestern Canada, headwater basins at the tundra-taiga transition are expected to experience earlier and larger spring runoff events (Krogh & Pomeroy, 2019). Projections for pan-Arctic and North American permafrost basins indicate seasonal variability in maximum flows, with significant changes in timing and magnitude across regions (Bennett et al., 2023). For the Mackenzie River Basin, annual streamflow is projected to increase by 2.3% per decade under intermediate emissions scenarios (SSP2-4.5) and 4.9% per decade under very high emissions scenarios (SSP5-8.5), with spring snowmelt onset occurring earlier in response to warming (Zhang et al., 2023). These changes highlight the influence of climate-induced shifts in precipitation and snowmelt on the hydrology of high-latitude regions.

5.7.3.3: Central Canada

Shifts in temperature and precipitation patterns are altering hydrological regimes across southern Ontario. In watersheds such as the Grand and Credit rivers, earlier high flows are observed, with increased streamflow in winter months and reduced flows by spring (Champagne et al., 2019). Projections in the Grand River indicate pronounced increases in freshet streamflow under both intermediate (SSP2-4.5) and high (SSP3-7.0) emissions scenarios, driven by earlier snowmelt and changing precipitation dynamics (Dietrich, 2019). In contrast, watersheds like the South Nation River, in eastern Ontario, are projected to experience fewer and less intense annual spring floods because of earlier peak flows and reduced spring discharge intensity (Champagne et al., 2020). Under high emissions scenarios, early spring flows and lower annual maximum flows are also anticipated for watersheds such as the Groundhog River, in northeastern Ontario, from 2059 to 2098 (Champagne et al., 2023).

Hydrological regimes in Quebec exhibit varying responses to warming. Projections for the Nicolet River watershed suggest a shift in peak flows to the winter season, increasing the probability of winter flooding (Jiang et al., 2020). Southern Quebec watersheds show sensitivity to incremental warming: under a scenario with a 1°C global warming level and an associated 20% precipitation increase in southern Quebec, peak spring flows show increases and occur earlier. However, for projections with global warming levels above 1°C, peak flows are expected to decline, with further changes in timing and intensity (Aygün et al., 2020). These shifts point to potential temperature thresholds in determining future flood risks in the region.

5.7.3.4: Atlantic Canada

Atlantic Canada is experiencing a growing influence of climate change on regional flooding. In 2019, record-breaking water levels along the Saint John River, driven by snowmelt and intense rainfall, resulted in one of the region’s longest flood events, displacing communities and damaging infrastructure. Along the Atlantic coast, excessive winter precipitation, strong storm surges, and snow accumulation are contributing to frequent coastal flooding, particularly in Newfoundland and Labrador, including the Avalon Peninsula (Jalili Pirani & Najafi, 2020; Mostofi Zadeh et al., 2020). The increasing frequency and intensity of extreme flow events indicate an increasing chance of flooding across the region.

5.7.4: Confidence terms in key messages: summary of evidence

Key message 5.9: Over the period of observation, there have been no consistent trends in streamflow flood events across the country (high confidence). Streamflow-related floods in Canada are driven by multiple factors, including extreme precipitation, rapid snowmelt, rain-on-snow events, and ice jams, with complex interactions among these drivers.

Key message 5.10: Projected increases in extreme precipitation are expected to lead to more frequent and intense flash flooding across Canada (high confidence). Warmer temperatures are expected to lead to the earlier occurrence of snowmelt, rain-on-snow events, and ice jam breakups, resulting in earlier streamflow-related spring floods (medium confidence). However, their future frequency remains uncertain because of the interactions among rising temperatures, reduced snow cover, and the complex dynamics of ice jam–related and snowmelt-related floods. 

The assessment of streamflow-related flooding highlights the complexity of these events, which are often influenced by a combination of climatic, cryospheric, hydrological, and human factors. Although there have been increases in high-flow events in some regions of the country, past changes in flood frequency and magnitude vary significantly across Canada. There are no detectable increasing trends in streamflow-related floods for the country as a whole. Therefore, we have high confidence in the first key message.

Regarding the second key message, multiple studies project increases in the frequency and intensity of extreme precipitation that are consistent across the country (Chapter 8, section 8.3), thus providing high confidence in the increased occurrence of future flash flooding across Canada (including urban floods). Our medium confidence in the projected shift in the timing of spring floods related to ice jams, ROS events, and snowmelt to earlier in the year is supported by the projected higher winter and spring temperatures (Chapter 3, section 3.4), the many studies that have reported earlier snowmelt and shifts in peak streamflow timing over the past few decades associated with climate warming, and the many studies that project these changes will continue with future warming. Our confidence level is restricted to medium because of the complexity of factors associated with snowmelt-related flooding and the lack of studies on future flooding across Canada. The statement regarding the uncertainty of their future frequency—because of the interactions of rising temperatures, reduced snow cover, and the complex dynamics of snowmelt-related floods–is a factual statement.

5.8: Key knowledge gaps and emerging issues

Significant knowledge gaps exist in the assessment of past water cycle–related changes and their impacts on freshwater availability across Canada. These gaps are mainly due to the lack of long-term, consistent atmospheric, surface, and subsurface water observations across Canada. For example, fewer than 600 of Canada’s lakes are currently monitored for water level by the National Hydrometric Network, while the density and continuity of the groundwater level data from well networks across Canada are inconsistent and not archived and evaluated at the national level. Similarly, the number of weather stations across Canada has been reduced to the same as the number in the early 20th century (Mekis et al., 2018). Furthermore, these observational limitations also exist in atmospheric components (evaporation, large-scale moisture transport, etc.) and cryospheric components (snow cover, snow water equivalent, etc.) of the water cycle discussed in chapters 2, 4, and 6. Given these data limitations, producing a Canada-wide assessment of past trends in freshwater is challenging. A potential partial solution to these temporal and spatial inconsistencies lies in remote-sensing (satellite) technologies. These technologies include the Surface Water and Ocean Topography mission, which is designed to assess changing volumes of freshwater around the globe at an unprecedented resolution, the Gravity Recovery and Climate Experiment, which has been and will continue to be used to quantify gradual changes in groundwater storage on a national scale, and the Soil Moisture Active Passive mission, which currently provides continuous estimates of soil moisture for Canada as a whole (Bonsal et al., 2019).

Past effects of climate change on surface and subsurface freshwater are also difficult to quantify because of the complexity and diversity of freshwater systems across Canada, as well as numerous influences from human-related factors, such as dams and diversions, water withdrawals (e.g., groundwater pumping for domestic use and irrigation), and land use changes (e.g., urbanization and wetland drainage). These factors are likely to increase in the future, in part as adaptation measures to mitigate the impacts of climate change.

As outlined in this chapter, future water cycle–related changes and their impacts on freshwater availability across Canada are primarily assessed using a cascade of numerical models. For both surface and subsurface freshwater changes, the assessment often involves using climate-related changes from an ensemble of GCMs or RCMs, which simulate atmospheric conditions, such as temperature, precipitation, wind, and atmospheric circulation, incorporated into a hydrologic or groundwater model. In some cases, streamflow and water levels can be taken directly from the GCMs or RCMs. Although significant progress is being made in improving the predictive capability of modelling tools and in some cases understanding and reducing uncertainty in model results, challenges remain because of the significant degree of model uncertainty, especially when several different types of models are involved. As with past changes, the complexity and diversity of surface and subsurface freshwater systems across Canada, along with the influence of human-induced alterations to freshwater systems, including land use changes and the construction of dams and diversions, add to this uncertainty.

5.9: Synthesis of water cycle changes

Key message 5.11: There has been a shift in the timing of many water cycle–related processes to earlier in the spring (high confidence). The shifts include earlier occurrences of snowmelt, spring freshet, groundwater aquifer recharge, and freshwater ice-free dates. These changes are projected to continue (high confidence) with possible consequences for future freshwater security.

Key message 5.12: Canada’s water cycle has been altered and will continue to be altered by climate warming (medium confidence). This involves more precipitation, changes in the proportion of rainfall versus snowfall, increases in warm-season evaporation, and a greater potential for flash flooding and summer drought. These changes are expected to directly impact the availability of surface and subsurface freshwater across Canada. 

Our confidence in the synthesis key messages is based on the assessments of confidence in earlier key messages and supported by the evidence in the relevant sections.

This synthesis assessment focuses on past and future climate-related changes in the water cycle as they affect freshwater availability across Canada. A diagram of this synthesis assessment is provided in Figure 5.20.

Warming temperatures are having considerable effects on Canada’s freshwater availability, mainly by affecting precipitation and evaporation, the two main atmospheric components of the water cycle, as well as by shrinking many components of the cryosphere. These effects are expected to continue. In particular, human-caused climate warming has increased total precipitation amounts (chapters 2 and 3), caused changes in the proportion of rainfall versus snowfall (section 5.2; Chapter 2), and resulted in more heavy precipitation events (sections 5.2, 5.7; Chapter 8), all of which are projected to continue. Human-caused climate warming is also increasing warm-season evaporation from the land surface and over open water because of longer ice-free seasons. Furthermore, Canada’s cryosphere has been shrinking and will continue to do so. The critical cryosphere effects on Canada’s freshwater availability include less snow cover, an earlier snowmelt, glacier retreat, and thawing permafrost in northern Canada (Chapter 6).

Figure take-away: Past and future warming influence all aspects of Canada’s water cycle and freshwater availability.

Figure 5.20: Diagram summarizing how warming temperatures have influenced and are projected to continue to influence Canada’s water cycle and resulting freshwater availability. The statements in the text boxes are representative of general findings in Ch. 5. The chapter key messages provide more detailed assessed findings. The assessment of different topics is contained within multiple chapters of CCCR2026 as indicated by the chapter and section specific notations.

Changes in the atmospheric and cryospheric components of the water cycle are affecting surface and subsurface freshwater availability, as well as the occurrence of hydroclimatic extremes, including droughts and floods (Figure 5.20). Some of the greatest effects are on streamflow, where past and future changes in seasonal flow involve increases during winter and, for the most part, decreases during summer. Annual flow has increased in more northern regions of the country, and this is projected to continue. The seasonal flow changes, along with earlier and smaller spring freshets caused by warming temperatures, are resulting in changing streamflow regimes from more nival to pluvial regimes. These regime changes are also projected to continue.

Surface water in the form of lakes and wetlands is also affected by warming temperatures, but the changes are more varied when compared to streamflow. Researchers anticipate that future levels will fall in some regions and rise in others because of the many complex factors that affect surface water storage. These factors include the balance between increased open-water evaporation due to higher temperatures and longer ice-free periods, and projected increases in precipitation. In addition, surface water in northern regions is affected by permafrost thaw and associated lake drainage or in some cases lake expansion. All these factors affect surface water levels and are being influenced by a warming climate.

Changes in air temperature, precipitation, and the cryosphere are also affecting groundwater. Given earlier snowmelt and more cold-season precipitation falling as rain, future groundwater recharge of aquifers is projected to occur earlier in the year. Furthermore, evidence shows that groundwater is expected to remain one of the more resilient freshwater resources in a changing climate in the future when compared to surface water across the country. However, given the limited data and the complexity of groundwater systems and their interactions with surface water and climate, assessing changes in Canada’s groundwater systems is difficult.

Warmer temperatures, changes in precipitation and evaporation, and decreases in snow and ice are projected to affect the occurrence of hydroclimatic extreme events, namely droughts and floods. In addition, as shown in Figure 5.20, hydroclimatic extremes also influence the availability of surface and subsurface freshwater. Both meteorological and agricultural droughts are projected to increase in frequency and intensity, mainly across central and southern Canada during summer. This projected increase is mostly due to higher evapotranspiration not being balanced by increased precipitation. Summer hydrological droughts are also projected to increase in many regions of southern Canada, mainly because of increased evaporation and lower runoff from mountainous regions.

Streamflow-related floods in Canada are driven by multiple factors (extreme precipitation, rapid snowmelt, rain-on-snow events, and ice jams), with complex interactions among these drivers. The projected increases in extreme precipitation are anticipated to increase the occurrence of future flash flooding, including urban floods. However, there is considerable uncertainty about the projected occurrence of spring floods due to rapid snowmelt, rain-on-snow events, and ice jams. Rising temperatures and increased precipitation have the potential to increase rapid snowmelt and rain-on-snow floods, while decreased snowfall and thinner ice covers may reduce the occurrence of spring flooding, including floods related to river ice jams. As with other freshwater-related variables, warmer future temperatures are projected to result in earlier spring floods.

All these processes (Figure 5.20) have altered the historical water balance and resulting freshwater availability in many regions across the country and will continue to do so. The most identifiable effect involves a shift in the timing of many processes—such as snowmelt, spring freshet, groundwater aquifer recharge, and ice-free dates—to earlier in the spring (sections 5.2.1, 5.3.1, 5.3.2, 5.4.2, 5.5.1, 5.7.1, and 5.7.2). In addition, Canada’s water cycle is and will continue to be altered by increases in precipitation, changes in the proportion of rainfall versus snowfall, increased warm-season evaporation from both the land surface and open water, and greater potential for flash flooding and summer drought (sections 5.2.2, 5.4.2.2, 5.6.3, 5.7.2, and 5.7.3).

References

Adams, J. R., McNairn, H., Berg, A. A., & Champagne, C. (2015). Evaluation of near-surface soil moisture data from an AAFC monitoring network in Manitoba, Canada: Implications for L-band satellite validation. Journal of Hydrology, 521, 582–592.

Agboma, C., & Itenfisu, D. (2020). Investigating the spatio-temporal dynamics in the soil water storage in Alberta’s agricultural region. Journal of Hydrology, 588, 125104.

Ahmari, H., Blais, E.-L., & Greshuk, J. (2016). The 2014 flood event in the Assiniboine River Basin: Causes, assessment and damage. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 41(1–2), 85–93.

Alberta Disaster Financial Assistance Program. (2025). Alberta disaster financial assistance program (PDF).

Allan, R. P., Barlow, M., Byrne, M. P., Cherchi, A., Douville, H., Fowler, H. J., Gan, T. Y., Pendergrass, A. G., Rosenfeld, D., Swann, A. L. S., Wilcox, L. J., & Zolina, O. (2020). Advances in understanding large‐scale responses of the water cycle to climate change. Annals of the New York Academy of Sciences, 1472(1), 49–75.

Allan, R. P., & Soden, B. J. (2008). Atmospheric warming and the amplification of precipitation extremes. Science, 321(5895), 1481–1484.

Almonte, J. D., & Stewart, R. E. (2019). Precipitation transition regions over the southern Canadian Cordillera during January–April 2010 and under a pseudo-global-warming assumption. Hydrology and Earth System Sciences, 23(9), 3665–3682.

Ambadan, J. T., MacRae, H. C., Colliander, A., Tetlock, E., Helgason, W., Gedalof, Z., & Berg, A. A. (2022). Evaluation of SMAP soil moisture retrieval accuracy over a boreal forest region IEEE Transactions on Geoscience and Remote Sensing, 60, 1–11.

Ambadan, J. T., Oja, M., Gedalof, Z., & Berg, A. A. (2020). Satellite-observed soil moisture as an indicator of wildfire risk. Remote Sensing, 12(10), 1543.

Ammar, M. E., Gharib, A., Islam, Z., Davies, E. G. R., Seneka, M., & Faramarzi, M. (2020). Future floods using hydroclimatic simulations and peaks over threshold: An alternative to nonstationary analysis inferred from trend tests. Advances in Water Resources, 136, 103463.

Anis, M. R., & Sauchyn, D. J. (2021). Ensemble projection of future climate and surface water supplies in the north Saskatchewan River Basin above Edmonton, Alberta, Canada. Water, 13(17), 2425.

Anis, M. R., & Sauchyn, D. J. (2022). Ensemble climate and streamflow projections for the Assiniboine River Basin, Canada. Sustainability, 14(11), Article 11.

Armstrong, R. N., Pomeroy, J. W., & Martz, L. W. (2015). Variability in evaporation across the Canadian Prairie region during drought and non-drought periods. Journal of Hydrology, 521, 182–195.

Arora, V. K., Lima, A., & Shrestha, R. (2025). The effect of climate change on the simulated streamflow of six Canadian rivers based on the CanRCM4 regional climate model. Hydrology and Earth System Sciences, 29(1), 291–312.

Arvidsson, A., Blomqvist, G., & Oberg, G. (2012). Impact of climate change on use of anti-icing and deicing salt in Sweden. Winter maintenance and surface transportation weather: international conference on winter maintenance and surface transportation weather, Coralville: IA.

Asong, Z. E., Wheater, H. S., Bonsal, B., Razavi, S., & Kurkute, S. (2018). Historical drought patterns over Canada and their teleconnections with large-scale climate signals. Hydrology and Earth System Sciences, 22(6), 3105–3124.

Assani, A. A. (2022). Variability of mean annual flows in southern Quebec (Canada). Water, 14(9), 1370.

Audlaluk, L. (2020). What I remember, what I know: The life of a High Arctic exile. Inhabit Media Incorporated.

Aygün, O., Kinnard, C., Campeau, S., & Krogh, S. A. (2020). Shifting hydrological processes in a Canadian agroforested catchment due to a warmer and wetter climate. Water, 12(3), Article 3.

Bakaic, M., & Medeiros, A. S. (2017). Vulnerability of northern water supply lakes to changing climate and demand. Arctic Science, 3(1), 1–16.

Balting, D. F., AghaKouchak, A., Lohmann, G., & Ionita, M. (2021). Northern hemisphere drought risk in a warming climate. Npj Climate and Atmospheric Science, 4(1), 61.

Beguería, S., Vicente-Serrano, S. M., Reig, F., & Latorre, B. (2014). Standardized precipitation evapotranspiration index (SPEI) revisited: Parameter fitting, evapotranspiration models, tools, datasets and drought monitoring. International Journal of Climatology, 34(10), 3001–3023.

Beltaos, S., & Bonsal, B. (2021). Climate change impacts on Peace River ice thickness and implications to ice-jam flooding of Peace-Athabasca Delta, Canada. Cold Regions Science and Technology, 186, 103279.

Beltaos, S., & Prowse, T. D. (2001). Climate impacts on extreme ice-jam events in Canadian rivers. Hydrological Sciences Journal, 46(1), 157–181.

Bennett, K. E., Schwenk, J., Bachand, C., Gasarch, E., Stachelek, J., Bolton, W. R., & Rowland, J. C. (2023). Recent streamflow trends across permafrost basins of North America. Frontiers in Water, 5, 1099660.

Berg, A. A., Wicks, K., Ambadan, J. T., Roy, A., Magagi, R., Helgason, W., Colliander, A., Alijani, Z., Amini, Y., Cosh, M. H., Creen, J., Gorrab, A., MacRae, H., McDonald, K., Millard, K., Misra, S., Muhuri, A., Ogut, M., Riis, N., … Yueh, S. (2025). Soil moisture active/passive validation experiment within the Canadian Boreal Forest in 2022 (SMAPVEX22-boreal). IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 18, 11816–11834.

Berg, A., & Sheffield, J. (2018). Climate change and drought: The soil moisture perspective. Current Climate Change Reports, 4(2), 180–191.

Berg, A., Sheffield, J., & Milly, P. C. D. (2017). Divergent surface and total soil moisture projections under global warming. Geophysical Research Letters, 44(1), 236–244.

Berthot, L., St-Hilaire, A., Caissie, D., El-Jabi, N., Kirby, J., & Ouellet-Proulx, S. (2021). Environmental flow assessment in the context of climate change: A case study in Southern Quebec (Canada). Journal of Water and Climate Change, 12(8), Article 8.

Bhatti, A. Z., Farooque, A. A., Li, Q., Abbas, F., & Acharya, B. (2021). Spatial distribution and sustainability implications of the Canadian groundwater resources under changing climate. Sustainability, 13(17), 9778.

Blanken, P. D., Rouse, W. R., Culf, A. D., Spence, C., Boudreau, L. D., Jasper, J. N., Kochtubajda, B., Schertzer, W. M., Marsh, P., & Verseghy, D. (2000). Eddy covariance measurements of evaporation from Great Slave Lake, Northwest Territories, Canada. Water Resources Research, 36(4), 1069–1077.

Blauhut, V. (2020). The triple complexity of drought risk analysis and its visualisation via mapping: A review across scales and sectors. Earth-Science Reviews, 210, 103345.

Bonsal, B. R., Cuell, C., Wheaton, E., Sauchyn, D. J., & Barrow, E. (2017). An assessment of historical and projected future hydro‐climatic variability and extremes over southern watersheds in the Canadian Prairies. International Journal of Climatology, 37(10), 3934–3948.

Bonsal, B. R., Peters, D. L., Seglenieks, F., Rivera, A., & Berg, A. (2019). Changes in freshwater availability across Canada. In E. Bush & D. S. Lemmen (Eds), Canada’s Changing Climate Report (pp. 261–342). Government of Canada.

Bonsal, B. R., & Prowse, T. D. (2003). Trends and variability in spring and autumn 0°C-isotherm dates over Canada. Climatic Change, 57(3), 341–358.

Bonsal, B. R., Shrestha, R. R., Dibike, Y., Peters, D. L., Spence, C., Mudryk, L., & Yang, D. (2020). Western Canadian freshwater availability: Current and future vulnerabilities. Environmental Reviews, 28(4), 528–545.

Bonsal, B. R., Tam, B., Zhang, X., Li, G., Philps, L., & Rong, R. (2024). Do meteorological, agricultural, and hydrological indicators all point to an increased frequency and intensity of droughts across Canada under a changing climate? Atmosphere-Ocean, 62(5), 372–390.

Bonsal, B. R., Wheaton, E. E., Chipanshi, A. C., Lin, C., Sauchyn, D. J., & Wen, L. (2011). Drought research in Canada: A review. Atmosphere-Ocean, 49(4), 303–319.

Boumaiza, L., Walter, J., Chesnaux, R., Lambert, M., Jha, M. K., Wanke, H., Brookfield, A., Batelaan, O., Galvão, P., Laftouhi, N., & Stumpp, C. (2022). Groundwater recharge over the past 100 years: Regional spatiotemporal assessment and climate change impact over the Saguenay‐Lac‐Saint‐Jean region, Canada. Hydrological Processes, 36(3), e14526.

Box, J. E., Colgan, W. T., Christensen, T. R., Schmidt, N. M., Lund, M., Parmentier, F.-J. W., Brown, R., Bhatt, U. S., Euskirchen, E. S., Romanovsky, V. E., Walsh, J. E., Overland, J. E., Wang, M., Corell, R. W., Meier, W. N., Wouters, B., Mernild, S., Mård, J., Pawlak, J., & Olsen, M. S. (2019). Key indicators of Arctic climate change: 1971–2017. Environmental Research Letters, 14(4), 045010.

Boyer, D., & Howe, C. (2024, August 17). Global glacier casualty list. Global Glacier Casuality List.

Budhathoki, S., Rokaya, P., & Lindenschmidt, K.-E. (2022). Impacts of future climate on the hydrology of a transboundary river basin in northeastern North America. Journal of Hydrology, 605, 127317.

Burn, D. H., & Hesch, N. M. (2007). Trends in evaporation for the Canadian prairies. Journal of Hydrology, 336(1–2), 61–73.

Burn, D. H., & Whitfield, P. H. (2016). Changes in floods and flood regimes in Canada. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 41(1–2), 139–150.

Burn, D. H., & Whitfield, P. H. (2017). Changes in cold region flood regimes inferred from long‐record reference gauging stations. Water Resources Research, 53(4), 2643–2658.

Burn, D. H., & Whitfield, P. H. (2018). Changes in flood events inferred from centennial length streamflow data records. Advances in Water Resources, 121, 333–349.

Burn, D. H., & Whitfield, P. H. (2023). Climate related changes to flood regimes show an increasing rainfall influence. Journal of Hydrology, 617, 129075.

Buttle, J. M., Allen, D. M., Caissie, D., Davison, B., Hayashi, M., Peters, D. L., Pomeroy, J. W., Simonovic, S., St-Hilaire, A., & Whitfield, P. H. (2016). Flood processes in Canada: Regional and special aspects. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 41(1–2), 7–30.

Byun, K., Chiu, C.-M., & Hamlet, A. F. (2019). Effects of 21st century climate change on seasonal flow regimes and hydrologic extremes over the Midwest and Great Lakes region of the US. Science of The Total Environment, 650, 1261–1277.

Canadian Council of Ministers of the Environment. (2010). Review and Assessment of Canadian Groundwater Resources, Management, Current Research Mechanisms and Priorities (PDF).

Cardinal, É., Thériault, J. M., Stewart, R. E., Thompson, H. D., & Déry, S. J. (2024). Climatology of and factors contributing to occurrences of near-0°C temperatures and associated precipitation at and near terrace, British Columbia, Canada. Atmosphere-Ocean, 62(2), Article 2.

Caretta, M. A., Mukherji, A., Renwick, J., Betts, R. A., Gelfan, A., Hirabayashi, Y., Lissner, T. K., Cherchi, A., Gunn, E. L., Liu, J., Morgan, R., Mwanga, S., Mba, W. P., & Supratid, S. (2022). Water. In Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (pp. 551–712). Cambridge University Press.

Carrera, M. L., Bilodeau, B., Bélair, S., Abrahamowicz, M., Russell, A., & Wang, X. (2019). Assimilation of passive L-band microwave brightness temperatures in the Canadian land data assimilation system: Impacts on short-range warm season numerical weather prediction. Journal of Hydrometeorology, 20(6), 1053–1079.

Champagne, C., Rowlandson, T., Berg, A., Burns, T., L’Heureux, J., Tetlock, E., Adams, J. R., McNairn, H., Toth, B., & Itenfisu, D. (2016). Satellite surface soil moisture from SMOS and Aquarius: Assessment for applications in agricultural landscapes. International Journal of Applied Earth Observation and Geoinformation, 45, 143–154.

Champagne, C., White, J., Berg, A., Belair, S., & Carrera, M. (2019). Impact of soil moisture data characteristics on the sensitivity to crop yields under drought and excess moisture conditions. Remote Sensing, 11(4), 372.

Champagne, O., Arain, A., Wang, S., & Leduc, M. (2023). Future change in amplitude and timing of high-flow events in a Canadian subarctic watershed. Cold Regions Science and Technology, 209, 103807.

Champagne, O., Arain, M. A., Leduc, M., Coulibaly, P., & McKenzie, S. (2020). Future shift in winter streamflow modulated by the internal variability of climate in southern Ontario. Hydrology and Earth System Sciences, 24(6), 3077–3096.

Chegwidden, O. S., Nijssen, B., Rupp, D. E., Arnold, J. R., Clark, M. P., Hamman, J. J., Kao, S.-C., Mao, Y., Mizukami, N., Mote, P. W., Pan, M., Pytlak, E., & Xiao, M. (2019). How do modeling decisions affect the spread among hydrologic climate change projections? Exploring a large ensemble of simulations across a diversity of hydroclimates. Earth’s Future, 7(6), 623–637.

Chen, J., Dai, A., Zhang, Y., & Rasmussen, K. L. (2020). Changes in convective available potential energy and convective inhibition under global warming. Journal of Climate, 33(6), 2025–2050.

Chen, Y., Cheng, X., Liu, A., Chen, Q., & Wang, C. (2023). Tracking lake drainage events and drained lake basin vegetation dynamics across the Arctic. Nature Communications, 14(1), 7359.

Chernos, M., MacDonald, R. J., Nemeth, M. W., & Craig, J. R. (2020). Current and future projections of glacier contribution to streamflow in the upper Athabasca River Basin. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 45(4), 324–344.

Chipanshi, A., Berry, M., Zhang, Y., Qian, B., & Steier, G. (2022a). Agroclimatic indices across the Canadian Prairies under a changing climate and their implications for agriculture. International Journal of Climatology, 42(4), 2351–2367.

Chipanshi, A., Berry, M., Zhang, Y., Qian, B., & Steier, G. (2022b). Agroclimatic indices across the Canadian prairies under a changing climate and their implications for agriculture. International Journal of Climatology, 42(4), 2351–2367.

Cho, E., McCrary, R. R., & Jacobs, J. M. (2021). Future changes in snowpack, snowmelt, and runoff potential extremes over North America. Geophysical Research Letters, 48(22), e2021GL094985.

Chu, C., Jones, N. E., Mandrak, N. E., Piggott, A. R., & Minns, C. K. (2008). The influence of air temperature, groundwater discharge, and climate change on the thermal diversity of stream fishes in southern Ontario watersheds. Canadian Journal of Fisheries and Aquatic Sciences, 65(2), 297–308.

Clark, M. P., Pietroniro, A., & Sandford, R. W. (2023). Commentary: Towards a new era of environmental prediction in Canada. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 48(3), 280–282.

Colliander, A., Cosh, M. H., Misra, S., Jackson, T. J., Crow, W. T., Powers, J., McNairn, H., Bullock, P., Berg, A., Magagi, R., Gao, Y., Bindlish, R., Williamson, R., Ramos, I., Latham, B., O’Neill, P., & Yueh, S. (2019). Comparison of high-resolution airborne soil moisture retrievals to SMAP soil moisture during the SMAP validation experiment 2016 (SMAPVEX16). Remote Sensing of Environment, 227, 137–150.

Colliander, A., Reichle, R. H., Crow, W. T., Cosh, M. H., Chen, F., Chan, S., Das, N. N., Bindlish, R., Chaubell, J., Kim, S., Liu, Q., O’Neill, P. E., Dunbar, R. S., Dang, L. B., Kimball, J. S., Jackson, T. J., Al-Jassar, H. K., Asanuma, J., Bhattacharya, B. K., … Yueh, S. H. (2022). Validation of soil moisture data products from the NASA SMAP mission. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 15, 364–392.

Conway-White, O., Steelman, C. M., & Rudolph, D. L. (2025). Assessing permafrost distribution in northern watersheds using airborne and surface electrical measurements, IAH Canadian chapter annual conference.

Cook, B. I., Ault, T. R., & Smerdon, J. E. (2015). Unprecedented 21st century drought risk in the American Southwest and Central Plains. Science Advances, 1(1), e1400082.

Cook, B. I., Mankin, J. S., & Anchukaitis, K. J. (2018). Climate change and drought: From past to future. Current Climate Change Reports, 4(2), 164–179.

Cook, B. I., Mankin, J. S., Marvel, K., Williams, A. P., Smerdon, J. E., & Anchukaitis, K. J. (2020). Twenty‐first century drought projections in the CMIP6 forcing scenarios. Earth’s Future, 8(6), e2019EF001461.

Costa, D., Zhang, H., & Levison, J. (2021). Impacts of climate change on groundwater in the Great Lakes Basin: A review. Journal of Great Lakes Research, 47(6), 1613–1625.

Cuthbert, M. O., Gleeson, T., Moosdorf, N., Befus, K. M., Schneider, A., Hartmann, J., & Lehner, B. (2019). Global patterns and dynamics of climate–groundwater interactions Nature Climate Change, 9(2), 137–141.

Dai, A. (2013). Increasing drought under global warming in observations and models. Nature Climate Change, 3(1), 52–58.

David. (2019). Impacts of the extreme 2019 great lakes high water levels felt throughout lake Ontario and the St. Lawrence River.

DeBeer, C. M., Wheater, H. S., Carey, S. K., & Chun, K. P. (2016). Recent climatic, cryospheric, and hydrological changes over the interior of western Canada: A review and synthesis. Hydrology and Earth System Sciences, 20(4), 1573–1598.

DeBeer, C. M., Wheater, H. S., Pomeroy, J. W., Barr, A. G., Baltzer, J. L., Johnstone, J. F., Turetsky, M. R., Stewart, R. E., Hayashi, M., van der Kamp, G., Marshall, S., Campbell, E., Marsh, P., Carey, S. K., Quinton, W. L., Li, Y., Razavi, S., Berg, A., McDonnell, J. J., … Pietroniro, A. (2021). Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada – Part 2: Future change in cryosphere, vegetation, and hydrology. Hydrology and Earth System Sciences, 25(4), 1849–1882.

Derksen, C., Burgess, D., Duguay, C., Howell, S., Murdyk, L., Smith, S., Thackeray, C., & Kirchmeier-Young, M. (2019). Changes in snow, ice, and permafrost across Canada.

Déry, S. J., Stadnyk, T. A., MacDonald, M. K., & Gauli-Sharma, B. (2016). Recent trends and variability in river discharge across northern Canada. Hydrology and Earth System Sciences, 20(12), 4801–4818.

Déry, S. J., Stahl, K., Moore, R. D., Whitfield, P. H., Menounos, B., & Burford, J. E. (2009). Detection of runoff timing changes in pluvial, nival, and glacial rivers of western Canada. Water Resources Research, 45(4), 2008WR006975.

Dethier, E. N., Sartain, S. L., Renshaw, C. E., & Magilligan, F. J. (2020). Spatially coherent regional changes in seasonal extreme streamflow events in the United States and Canada since 1950. Science Advances, 6(49), Article 49.

Dettinger, M. (2011). Climate change, atmospheric rivers, and floods in California—A multimodel analysis of storm frequency and magnitude changes. JAWRA Journal of the American Water Resources Association, 47(3), 514–523.

Dibike, Y., Eum, H.-I., & Prowse, T. (2018). Modelling the Athabasca watershed snow response to a changing climate. Journal of Hydrology: Regional Studies, 15, 134–148.

Dibike, Y., Muhammad, A., Shrestha, R. R., Spence, C., Bonsal, B., de Rham, L., Rowley, J., Evenson, G., & Stadnyk, T. (2021). Application of dynamic contributing area for modelling the hydrologic response of the Assiniboine River basin to a changing climate. Journal of Great Lakes Research, 47(3), 663–676.

Dibike, Y., Prowse, T., Bonsal, B., & O’Neil, H. (2017). Implications of future climate on water availability in the western Canadian river basins. International Journal of Climatology, 37(7), 3247–3263.

Dierauer, J. R., Allen, D. M., & Whitfield, P. H. (2019). Snow drought risk and susceptibility in the western United States and southwestern Canada. Water Resources Research, 55(4), 3076–3091.

Dierauer, J. R., Allen, D. M., & Whitfield, P. H. (2021). Climate change impacts on snow and streamflow drought regimes in four ecoregions of British Columbia. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 46(4), 168–193.

Dietrich, A. (2019). Climate change impacts on snowmelt-driven streamflow in the grand river watershed: Implications for water resource management [Master’s thesis, University of Waterloo].

Diffenbaugh, N. S., Singh, D., Mankin, J. S., Horton, D. E., Swain, D. L., Touma, D., Charland, A., Liu, Y., Haugen, M., Tsiang, M., & Rajaratnam, B. (2017). Quantifying the influence of global warming on unprecedented extreme climate events. Proceedings of the National Academy of Sciences, 114(19), 4881–4886.

Douville, H., Raghavan, K., Renwick, J., Allan, R. P., Arias, P. A., Barlow, M., Cerezo-Mota, R., Cherchi, A., Gan, T. Y., Gergis, J., Jiang, D., Khan, A., Pokam Mba, W., Rosenfeld, D., Tierney, J., & Zolina, O. (2021). Water cycle changes. In V. Masson-Delmotte, P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, & B. Zhou (Eds), Climate change 2021: The physical science basis. Contribution of working group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (pp. 1055–1210). Cambridge University Press.

Du, X., Shrestha, N. K., & Wang, J. (2019). Assessing climate change impacts on stream temperature in the Athabasca River Basin using SWAT equilibrium temperature model and its potential impacts on stream ecosystem. Science of The Total Environment, 650, 1872–1881.

Durocher, M., Requena, A. I., Burn, D. H., & Pellerin, J. (2019). Analysis of trends in annual streamflow to the Arctic Ocean. Hydrological Processes, 33(7), 1143–1151.

Dwyer, J. G., & O’Gorman, P. A. (2017). Changing duration and spatial extent of midlatitude precipitation extremes across different climates. Geophysical Research Letters, 44(11), 5863–5871.

ECCC. (2016). Pan-Canadian framework on clean growth and climate change: Canada’s plan to address climate change and grow the economy (PDF). Environment and Climate Change Canada.

ECCC, & GNWT. (2020). Hydrological analysis for Great Slave Lake 2020 (PDF). Environment and Climate Change Canada (ECCC) and Government of Northwest Territories (GNWT).

Famiglietti, J. S., & Ferguson, G. (2021). The hidden crisis beneath our feet. Science, 372(6540), 344–345.

Famiglietti, J. S., Ryu, D., Berg, A. A., Rodell, M., & Jackson, T. J. (2008). Field observations of soil moisture variability across scales. Water Resources Research, 44(1), 2006WR005804.

Fang, X., & Pomeroy, J. W. (2023). Simulation of the impact of future changes in climate on the hydrology of Bow River headwater basins in the Canadian Rockies. Journal of Hydrology, 620, 129566.

Fatolazadeh, F., & Goïta, K. (2022). Reconstructing groundwater storage variations from GRACE observations using a new Gaussian-Han-Fan (GHF) smoothing approach. Journal of Hydrology, 604, 127234.

Federal, Provincial and Territorial Governments of Canada. (2010). Canadian biodiversity: Ecosystem status and trends 2010 (PDF). Canadian Councils of Resource Ministers.

Feng, B., Zhang, Y., & Bourke, R. (2021). Urbanization impacts on flood risks based on urban growth data and coupled flood models. Natural Hazards, 106(1), Article 1.

Ficklin, D. L., Hannah, D. M., Wanders, N., Dugdale, S. J., England, J., Klaus, J., Kelleher, C., Khamis, K., & Charlton, M. B. (2023). Rethinking river water temperature in a changing, human-dominated world. Nature Water, 1(2), Article 2.

Fiord, G. (2014, November 20). As glacier melts, Grise Fiord residents fear for water supply. CBC News.

Ford, G. (2014). Qikiqtani truth commission: Community histories 1950-1975 (PDF). Inhabit Media Inc.

Freeze, R. A., & Cherry, J. A. (1979). Groundwater. Prentice-Hall.

Gatien, P., Arsenault, R., Martel, J.-L., Khorsandi, M., & St-Hilaire, A. (2024). Evaluating the effects of climate change on river water temperature downstream of a hydropower reservoir in western Canada. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 0(0), 1–19.

Gervais, J. A., Kovach, R., Sepulveda, A., Al-Chokhachy, R., Joseph Giersch, J., & Muhlfeld, C. C. (2020). Climate-induced expansions of invasive species in the Pacific Northwest, North America: A synthesis of observations and projections. Biological Invasions, 22(7), 2163–2183.

Gibson, C. M., Chasmer, L. E., Thompson, D. K., Quinton, W. L., Flannigan, M. D., & Olefeldt, D. (2018). Wildfire as a major driver of recent permafrost thaw in boreal peatlands. Nature Communications, 9(1), 3041.

Gibson, J. J., Prowse, T. D., & Peters, D. L. (2006). Hydroclimatic controls on water balance and water level variability in Great Slave Lake. Hydrological Processes, 20(19), 4155–4172.

Gibson, J. J., Yi, Y., & Birks, S. J. (2019). Isotopic tracing of hydrologic drivers including permafrost thaw status for lakes across Northeastern Alberta, Canada: A 16-year, 50-lake assessment. Journal of Hydrology: Regional Studies, 26, 100643.

Gibson, J. J., Yi, Y., & Birks, S. J. (2020). Watershed, climate, and stable isotope data (oxygen-18 and deuterium) for 50 boreal lakes in the oil sands region, northeastern Alberta, Canada, 2002–2017. Data in Brief, 29, 105308.

Gillett, N. P., Cannon, A. J., Malinina, E., Schnorbus, M., Anslow, F., Sun, Q., Kirchmeier-Young, M., Zwiers, F., Seiler, C., Zhang, X., Flato, G., Wan, H., Li, G., & Castellan, A. (2022). Human influence on the 2021 British Columbia floods. Weather and Climate Extremes, 36, 100441.

Gimeno, L., Algarra, I., Eiras‐Barca, J., Ramos, A. M., & Nieto, R. (2021). Atmospheric river, a term encompassing different meteorological patterns. WIREs Water, 8(6), e1558.

Golnaraghi, M., Thistlethwaite, J., Henstra, D., & Stewart, C. (2020). Flood risk management in Canada: Building flood resilience in a changing climate (PDF). Geneva Association.

Gosling, S. N., Zaherpour, J., Mount, N. J., Hattermann, F. F., Dankers, R., Arheimer, B., Breuer, L., Ding, J., Haddeland, I., & Kumar, R. (2017). A comparison of changes in river runoff from multiple global and catchment-scale hydrological models under global warming scenarios of 1 C, 2 C and 3 C. Climatic Change, 141, 577–595.

Government of Quebec. (2025, July 28). Eligible expenses for homeowners and tenants in the event of flooding or other disasters. Quebec.

Grant, L., Vanderkelen, I., Gudmundsson, L., Tan, Z., Perroud, M., Stepanenko, V. M., Debolskiy, A. V., Droppers, B., Janssen, A. B. G., Woolway, R. I., Choulga, M., Balsamo, G., Kirillin, G., Schewe, J., Zhao, F., del Valle, I. V., Golub, M., Pierson, D., Marcé, R., … Thiery, W. (2021). Attribution of global lake systems change to anthropogenic forcing. Nature Geoscience, 14(11), Article 11.

Grenier, C., Anbergen, H., Bense, V., Chanzy, Q., Coon, E., Collier, N., Costard, F., Ferry, M., Frampton, A., Frederick, J., Gonçalvès, J., Holmén, J., Jost, A., Kokh, S., Kurylyk, B., McKenzie, J., Molson, J., Mouche, E., Orgogozo, L., … Voss, C. (2018). Groundwater flow and heat transport for systems undergoing freeze-thaw: Intercomparison of numerical simulators for 2D test cases. Advances in Water Resources, 114, 196–218.

Gronewold, A. D., Do, H. X., Mei, Y., & Stow, C. A. (2021). A tug‐of‐war within the hydrologic cycle of a continental freshwater basin. Geophysical Research Letters, 48(4), e2020GL090374.

Gronewold, A. D., & Stow, C. A. (2014). Water Loss from the Great Lakes. Science, 343(6175), 1084–1085.

Hanes, C. C., Wotton, M., Bourgeau-Chavez, L., Woolford, D. G., Bélair, S., Martell, D., & Flannigan, M. D. (2023). Evaluation of new methods for drought estimation in the Canadian Forest Fire Danger Rating System. International Journal of Wildland Fire.

Hanesiak, J. M., Stewart, R. E., Bonsal, B. R., Harder, P., Lawford, R., Aider, R., Amiro, B. D., Atallah, E., Barr, A. G., Black, T. A., Bullock, P., Brimelow, J. C., Brown, R., Carmichael, H., Derksen, C., Flanagan, L. B., Gachon, P., Greene, H., Gyakum, J., … Zha, T. (2011). Characterization and summary of the 1999–2005 Canadian Prairie drought. Atmosphere-Ocean, 49(4), 421–452.

Harpold, A. A., Dettinger, M., & Rajagopal, S. (2017, February 28). Defining snow drought and why it matters. EOS.

Harrington, J. S., Mozil, A., Hayashi, M., & Bentley, L. R. (2018). Groundwater flow and storage processes in an inactive rock glacier. Hydrological Processes, 32(20), 3070–3088.

Hayashi, M. (2020). Alpine hydrogeology: The critical role of groundwater in sourcing the headwaters of the world. Groundwater, 58(4), 498–510.

He, Z., & Pomeroy, J. W. (2023). Assessing hydrological sensitivity to future climate change over the Canadian southern boreal forest. Journal of Hydrology, 624, 129897.

Held, I. M., & Soden, B. J. (2006). Robust responses of the hydrological cycle to global warming. Journal of Climate, 19(21), 5686–5699.

Henstra, D., Thistlethwaite, J., Brown, C., & Scott, D. (2019). Flood risk management and shared responsibility: Exploring Canadian public attitudes and expectations. Journal of Flood Risk Management, 12(1), e12346.

Hoell, A., Parker, B.-A., Downey, M., Umphlett, N., Jencso, K., Akyuz, F. A., Peck, D., Hadwen, T., Fuchs, B., & Kluck, D. (2020). Lessons learned from the 2017 flash drought across the US Northern Great Plains and Canadian Prairies. Bulletin of the American Meteorological Society, 101(12), E2171–E2185.

Holloway, J. E., Lewkowicz, A. G., Douglas, T. A., Li, X., Turetsky, M. R., Baltzer, J. L., & Jin, H. (2020). Impact of wildfire on permafrost landscapes: A review of recent advances and future prospects. Permafrost and Periglacial Processes, 31(3), 371–382.

Houle, D., Marty, C., Augustin, F., Dermont, G., & Gagnon, C. (2020). Impact of climate change on soil hydro-climatic conditions and base cations weathering rates in forested watersheds in eastern Canada. Frontiers in Forests and Global Change, 3, 535397.

Hsu, H., & Dirmeyer, P. A. (2023). Uncertainty in projected critical soil moisture values in CMIP6 affects the interpretation of a more moisture‐limited world. Earth’s Future, 11(6), e2023EF003511.

Huang, X., & Rudolph, D. L. (2022). A hybrid analytical-numerical technique for solving soil temperature during the freezing process. Advances in Water Resources, 162, 104163.

Huang, Y., Jiang, Y., Jiang, B., Bailey, R. T., Masud, B., Smerdon, B., & Faramarzi, M. (2024). Modelling impacts of climate change on snow drought, groundwater drought, and their feedback mechanism in a snow-dominated watershed in western Canada. Journal of Hydrology, 636, 131342.

Hudon, C., Armellin, A., Gagnon, P., & Patoine, A. (2010). Variations in water temperatures and levels in the St. Lawrence River (Québec, Canada) and potential implications for three common fish species. Hydrobiologia, 647(1), 145–161.

Hulley, M., Watt, E., & Clarke, C. (2019). Annual discharge trends for Canadian rivers. International Journal of River Basin Management, 17(4), 423–434.

Huning, L. S., & AghaKouchak, A. (2020). Global snow drought hot spots and characteristics. Proceedings of the National Academy of Sciences, 117(33), 19753–19759.

Husain, S. Z., Alavi, N., Bélair, S., Carrera, M., Zhang, S., Fortin, V., Abrahamowicz, M., & Gauthier, N. (2016). The Multibudget Soil, Vegetation, and Snow (SVS) scheme for land surface parameterization: Offline warm season evaluation. Journal of Hydrometeorology, 17(8), 2293–2313.

Immerzeel, W. W., Lutz, A. F., Andrade, M., Bahl, A., Biemans, H., Bolch, T., Hyde, S., Brumby, S., Davies, B. J., Elmore, A. C., Emmer, A., Feng, M., Fernández, A., Haritashya, U., Kargel, J. S., Koppes, M., Kraaijenbrink, P. D. A., Kulkarni, A. V., Mayewski, P., … Baillie, J. E. M. (2020). Importance and vulnerability of the world’s water towers. Nature, 1–1.

Insurance Bureau of Canada. (2025a). Climate.

Insurance Bureau of Canada. (2025b). Flooding.

Insurance Bureau of Canada. (2025c). Water damage and flood protection.

IPCC. (2014). Climate change 2013 – The physical science basis: Working group I contribution to the fifth assessment report of the intergovernmental panel on climate change. Cambridge University Press.

IPCC. (2021). Summary for policymakers. In V. Masson-Delmotte, P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, & B. Zhou (Eds), Climate change 2021: The physical science basis. Contribution of working group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (p. 3−32). Cambridge University Press.

IPCC. (2022a). Climate change and land: IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems (1st edn). Cambridge University Press.

IPCC. (2022b). The ocean and cryosphere in a changing climate: Special report of the Intergovernmental Panel on Climate Change. Cambridge University Press.

Islam, S. U., Curry, C. L., Déry, S. J., & Zwiers, F. W. (2019). Quantifying projected changes in runoff variability and flow regimes of the Fraser River Basin, British Columbia. Hydrology and Earth System Sciences, 23(2), 811–828.

Islam, S. U., Hay, R. W., Déry, S. J., & Booth, B. P. (2019). Modelling the impacts of climate change on riverine thermal regimes in western Canada’s largest Pacific watershed. Scientific Reports, 9(1), 11398.

Jalili Pirani, F., & Najafi, M. R. (2020). Recent trends in individual and multivariate compound flood drivers in Canada’s coasts. Water Resources Research, 56(8), Article 8.

Jalili Pirani, F., & Najafi, M. R. (2022). Multivariate analysis of compound flood hazard across Canada’s Atlantic, Pacific and Great Lakes coastal areas. Earth’s Future, 10(8), Article 8.

Jalili Pirani, F., & Najafi, M. R. (2023a). Characterizing compound flooding potential and the corresponding driving mechanisms across coastal environments. Stochastic Environmental Research and Risk Assessment, 37(5), 1943–1961.

Jalili Pirani, F., & Najafi, M. R. (2023b). Nonstationary frequency analysis of compound flooding in Canada’s coastal zones. Coastal Engineering, 182, 104292.

James, T. S., Robin, C., Henton, J. A., & Craymer, M. (2021). Relative sea-level projections for Canada based on the IPCC Fifth Assessment Report and the NAD83v70VG national crustal velocity model. Natural Resources Canada.

Jasechko, S., Seybold, H., Perrone, D., Fan, Y., Shamsudduha, M., Taylor, R. G., Fallatah, O., & Kirchner, J. W. (2024). Rapid groundwater decline and some cases of recovery in aquifers globally. Nature, 625(7996), 715–721.

Jeong, D. I., & Sushama, L. (2018a). Rain-on-snow events over North America based on two Canadian regional climate models. Climate Dynamics, 50(1–2), Article 1–2.

Jeong, D. I., & Sushama, L. (2018b). Rain-on-snow events over North America based on two Canadian regional climate models. Climate Dynamics, 50(1–2), 303–316.

Jeong, D. I., Sushama, L., & Naveed Khaliq, M. (2014). The role of temperature in drought projections over North America. Climatic Change, 127(2), 289–303.

Jiang, Q., Qi, Z., Tang, F., Xue, L., & Bukovsky, M. (2020). Modeling climate change impact on streamflow as affected by snowmelt in Nicolet River Watershed, Quebec. Computers and Electronics in Agriculture, 178, 105756.

Kariyawasam, D. (2022). Changes in lake drainage in the western Canadian Arctic [Master’s thesis, Wilfred Laurier University].

Kerr. (1985). Future water levels and flows for great slave and great bear lakes, mackenzie river, and mackenzie delta (pp. 73–91) (PDF). Environment and Climate Change Canada and the University of British Columbia.

Kerr, Y. H., Waldteufel, P., Richaume, P., Wigneron, J. P., Ferrazzoli, P., Mahmoodi, A., Al Bitar, A., Cabot, F., Gruhier, C., Juglea, S. E., Leroux, D., Mialon, A., & Delwart, S. (2012). The SMOS soil moisture retrieval algorithm. IEEE Transactions on Geoscience and Remote Sensing, 50(5), 1384–1403.

Keung, C., Johnson, K., Gretton, J., & Alamgir, A. (2022). Hydrology and water balance study for the Canadian high Arctic community of Grise Fiord. Proceedings of the Canadian Society of Civil Engineering Annual Conference 2022. Canadian Society for Civil Engineering.

Khorsandi, M., St-Hilaire, A., Arsenault, R., Martel, J.-L., Larabi, S., Schnorbus, M., & Zwiers, F. (2023). Future flow and water temperature scenarios in an impounded drainage basin: Implications for summer flow and temperature management downstream of the dam. Climatic Change, 176(12), 164.

Kim, S. J., Asadzadeh, M., & Stadnyk, T. A. (2022). Climate change impact on water supply and hydropower generation potential in Northern Manitoba. Journal of Hydrology: Regional Studies, 41, 101077.

Kirchmeier-Young, M. C., Wan, H., & Zhang, X. (2021). Anthropogenic contribution to the rainfall associated with the 2019 Ottawa River flood. Bulletin of the American Meteorological Society, 102(1), S33–S38.

Kokelj, S. V., Gingras-Hill, T., Daly, S. V., Morse, P., Wolfe, S., Rudy, A. C. A., Van Der Sluijs, J., Weiss, N., O’Neill, B., Baltzer, J., Lantz, T. C., Gibson, C., Cazon, D., Fraser, R. H., Froese, D. G., Giff, G., Klengenberg, C., Lamoureux, S. F., Quinton, W., … Young, J. (2023). The Northwest Territories Thermokarst Mapping Collective: A northern-driven mapping collaborative toward understanding the effects of permafrost thaw. Arctic Science, AS-2023-0009.

Koshida, G., Cohen, S., & Mortsch, L. (2015). Climate and water availability indicators in Canada: Challenges and a way forward. Part II–Historic trends. Canadian Water Resources Journal/Revue Canadienne Des Ressources Hydriques, 40(2), 133-145.

Krogh, S. A., & Pomeroy, J. W. (2019). Impact of future climate and vegetation on the hydrology of an Arctic headwater basin at the Tundra–Taiga transition. Journal of Hydrometeorology, 20(2), 197–215.

Kromm, D. E., & White, S. E. (Eds). (1992). Groundwater exploitation in the high plains. University Press of Kansas.

Kurkute, S., Li, Z., Li, Y., & Huo, F. (2020). Assessment and projection of water budget over western Canada using convection permitting WRF simulations. Hydrology and Earth System Sciences, 24, 3677–3697.

Kurylyk, B. L., MacQuarrie, K. T. B., Caissie, D., & McKenzie, J. M. (2015, May 26). Shallow groundwater thermal sensitivity to climate change and land cover disturbances: Derivation of analytical expressions and implications for stream temperature modeling. Hydrology and Earth System Sciences, 2469–2489.

Lachance-Cloutier, S., Noel, P., Ricard, S., Turcotte, R., & Braun, M. (2015). Hydroclimatic atlas of southern Québec, the impact of climate change on high, low and mean flow regimes for the 2050 horizon. Centre d’expertise hydrique du Québec (CEHQ).

Lam, S., & Dokoska, K. (2022). Climate change in the great lakes basin: Summary of trends and impacts (PDF). Toronto and Region Conservation Authority.

Lantz, T. C., Zhang, Y., & Kokelj, S. V. (2022). Impacts of ecological succession and climate warming on permafrost aggradation in drained lake basins of the Tuktoyaktuk Coastlands, Northwest Territories, Canada. Permafrost and Periglacial Processes, 33(2), 176–192.

Larocque, M., Levison, J., Martin, A., & Chaumont, D. (2019). A review of simulated climate change impacts on groundwater resources in Eastern Canada. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 44(1), 22–41.

Lecavalier, C. (2024). Les propriétaires le bec à l’eau. La Presse.

Li, C., Liu, J., Du, F., Zwiers, F. W., & Feng, G. (2025). Increasing certainty in projected local extreme precipitation change. Nature Communications, 16(1), 850.

Li, C., Zwiers, F., Zhang, X., Li, G., Sun, Y., & Wehner, M. (2021). Changes in annual extremes of daily temperature and precipitation in CMIP6 models. Journal of Climate, 34(9), 3441–3460.

Li, J., & Wang, S. (2022). Seasonal variations and long-term trends of groundwater over the Canadian landmass. Hydrogeology Journal, 30(2), 401–415.

Li, Y., Li, Z., Zhang, Z., Chen, L., Kurkute, S., Scaff, L., & Pan, X. (2019). High-resolution regional climate modeling and projection over western Canada using a weather research forecasting model with a pseudo-global warming approach. Hydrology and Earth System Sciences, 23(11), Article 11.

Li, Z., Wang, S., & Li, J. (2020). Spatial variations and long-term trends of potential evaporation in Canada. Scientific Reports, 10(1), 22089.

Lilhare, R., Déry, S. J., Stadnyk, T. A., Pokorny, S., & Koenig, K. A. (2022). Warming soil temperature and increasing baseflow in response to recent and potential future climate change across northern Manitoba, Canada. Hydrological Processes, 36(11), e14748.

Livneh, B., & Badger, A. M. (2020). Drought less predictable under declining future snowpack. Nature Climate Change, 10(5), 452–458.

Lloyd-Hughes, B. (2014). The impracticality of a universal drought definition. Theoretical and Applied Climatology, 117, 607–611.

López-Moreno, J. I., Pomeroy, J. W., Alonso-González, E., Morán-Tejeda, E., & Revuelto, J. (2020). Decoupling of warming mountain snowpacks from hydrological regimes. Environmental Research Letters, 15(11), 114006.

Lucas-Picher, P., Lachance-Cloutier, S., Arsenault, R., Poulin, A., Ricard, S., Turcotte, R., & Brissette, F. (2021). Will evolving climate conditions increase the risk of floods of the large U.S.-Canada transboundary Richelieu River basin? JAWRA Journal of the American Water Resources Association, 57(1), 32–56.

MacDonald, D. D. (2004). Great Bear Lake: State of the knoweldge report (PDF). Northern Environmental Consulting.

MacDonald, M. K., Stadnyk, T. A., Déry, S. J., Braun, M., Gustafsson, D., Isberg, K., & Arheimer, B. (2018). Impacts of 1.5 and 2.0 °C warming on pan-arctic river discharge into the Hudson Bay complex through 2070. Geophysical Research Letters, 45(15), 7561–7570.

Macquet, M., Lawton, D., Osadetz, K., Maidment, G., Bertram, M., Hall, K., Kolkman-Quinn, B., Monsegny Parra, J., Race, K., Savard, G., Wang, Y., & Carbon Management Canada Team. (2022). Overview of carbon management Canada’s pilot-scale CO₂ injection site for developing and testing monitoring technologies for carbon capture and storage, and methane detection (PDF). Canadian Society of Exploration Geophysicist.

Magagi, R., Berg, A. A., Goita, K., Belair, S., Jackson, T. J., Toth, B., Walker, A., McNairn, H., O’Neill, P. E., Moghaddam, M., Gherboudj, I., Colliander, A., Cosh, M. H., Burgin, M., Fisher, J. B., Kim, S.-B., Mladenova, I., Djamai, N., Rousseau, L.-P. B., … Merzouki, A. (2013). Canadian experiment for soil moisture in 2010 (CanEx-SM10): Overview and preliminary results. IEEE Transactions on Geoscience and Remote Sensing, 51(1), 347–363.

Mailhot, E., Music, B., Nadeau, D. F., Frigon, A., & Turcotte, R. (2019). Assessment of the Laurentian great lakes’ hydrological conditions in a changing climate. Climatic Change.

Mankin, J. S., Viviroli, D., Mekonnen, M. M., Hoekstra, A. Y., Horton, R. M., Smerdon, J. E., & Diffenbaugh, N. S. (2017). Influence of internal variability on population exposure to hydroclimatic changes. Environmental Research Letters, 12(4), 044007.

Mantua, N., Tohver, I., & Hamlet, A. (2010). Climate change impacts on streamflow extremes and summertime stream temperature and their possible consequences for freshwater salmon habitat in Washington State. Climatic Change, 102(1), 187–223.

Mardian, J., Champagne, C., Bonsal, B., & Berg, A. (2023). A machine learning framework for predicting and understanding the Canadian drought monitor. Water Resources Research, 59(8), e2022WR033847.

Mardian, J., Champagne, C., Bonsal, B., Daneshfar, B., & Berg, A. (2024). From drought hazard to risk: A spring wheat vulnerability assessment in the Canadian Prairies. Agricultural and Forest Meteorology, 353, 110056.

Markle, J., & Harris, M. (2019). Groundwater levels in Ontario: A trend analysis using the provincial groundwater monitoring network. Ministry of the Environment.

Martel, J.-Luc., Brissette, F., Troin, M., Arsenault, R., Chen, J., Su, T., & Lucas‐Picher, P. (2022). CMIP5 and CMIP6 model projection comparison for hydrological impacts over North America. Geophysical Research Letters, 49(15), e2022GL098364.

Masud, M. B., Khaliq, M. N., & Wheater, H. S. (2017). Projected changes to short- and long-duration precipitation extremes over the Canadian Prairie provinces. Climate Dynamics, 49(5–6), 1597–1616.

Masud, M. B., Qian, B., & Faramarzi, M. (2020). Performance of multivariate and multiscalar drought indices in identifying impacts on crop production. International Journal of Climatology, 40(1), 292–307.

McAfee, S. A. (2013). Methodological differences in projected potential evapotranspiration. Climatic Change, 120(4), 915–930.

McCollum, C., & Ibáñez, I. (2020). Soil moisture gradients and climate change: Predicting growth of a critical boreal tree species. Canadian Journal of Forest Research, 50(10), 1074–1080.

McCullough, G. K. (2015). Climate in the Lake Winnipeg watershed and the level of Lake Winnipeg (PDF). Manitoba Clean Environment Commission.

McKenzie, J. M., Kurylyk, B. L., Walvoord, M. A., Bense, V. F., Fortier, D., Spence, C., & Grenier, C. (2021). Invited perspective: What lies beneath a changing Arctic? The Cryosphere, 15(1), 479–484.

McMahon, T. A., Peel, M. C., Lowe, L., Srikanthan, R., & McVicar, T. R. (2013). Estimating actual, potential, reference crop and pan evaporation using standard meteorological data: A pragmatic synthesis. Hydrology and Earth System Sciences, 17(4), 1331–1363.

McNairn, H., Jackson, T. J., Wiseman, G., Belair, S., Berg, A., Bullock, P., Colliander, A., Cosh, M. H., Kim, S.-B., Magagi, R., Moghaddam, M., Njoku, E. G., Adams, J. R., Homayouni, S., Ojo, E., Rowlandson, T., Shang, J., Goita, K., & Hosseini, M. (2015). The soil moisture active passive validation experiment 2012 (SMAPVEX12): Prelaunch calibration and validation of the SMAP soil moisture algorithms. IEEE Transactions on Geoscience and Remote Sensing, 53(5), 2784–2801.

Mekis, E., Donaldson, N., Reid, J., Zucconi, A., Hoover, J., Li, Q., Nitu, R., & Melo, S. (2018). An overview of surface-based precipitation observations at environment and climate change Canada. Atmosphere-Ocean, 56(2), 71–95.

Mekis, E., Stewart, R. E., Theriault, J. M., Kochtubajda, B., Bonsal, B. R., & Liu, Z. (2020). Near-0 °C surface temperature and precipitation type patterns across Canada. Hydrology and Earth System Sciences, 24(4), 1741–1761.

Merzouki, A., McNairn, H., Powers, J., & Friesen, M. (2019). Synthetic Aperture Radar (SAR) compact polarimetry for soil moisture retrieval. Remote Sensing, 11(19), 2227.

Messager, M. L., Lehner, B., Cockburn, C., Lamouroux, N., Pella, H., Tockner, K., Watt, C., & Datry, T. (2021). Global prevalence of non-perennial rivers and streams. Nature, 594(7863), 391–397.

Milrad, S. M., Atallah, E. H., & Gyakum, J. R. (2009). Dynamical and precipitation structures of poleward-moving tropical cyclones in eastern Canada, 1979–2005. Monthly Weather Review, 137(3), 836–851.

Mohammed, A. A., Guimond, J. A., Bense, V. F., Jamieson, R. C., McKenzie, J. M., & Kurylyk, B. L. (2022). Mobilization of subsurface carbon pools driven by permafrost thaw and reactivation of groundwater flow: A virtual experiment. Environmental Research Letters, 17(12), 124036.

Mohanty and Simonovic. (2021). Changes in floodplain regimes over Canada due to climate change impacts: Observations from CMIP6 models. Science of the Total Environment, 792, 148323.

Moore, D., Sidle, R. C., Eaton, B., & Gomi, T. (Eds). (2017). Water and watersheds. In Sustainable forest management: From concept to practice (p. 28). Routledge.

Mostofi Zadeh, S., Burn, D. H., & O’Brien, N. (2020). Detection of trends in flood magnitude and frequency in Canada. Journal of Hydrology: Regional Studies, 28, 100673.

Mousavi, R., Johnson, D. L., Byrne, J. M., & Kroebel, R. (2024). Projected 21st century drought condition in the south Saskatchewan River watershed: A case study in the Canadian Prairies. Atmosphere, 15(11), 1292.

Murray, J., Ayers, J., & Brookfield, A. (2023). The impact of climate change on monthly baseflow trends across Canada. Journal of Hydrology, 618, 129254.

Music, B., Frigon, A., Lofgren, B., Turcotte, R., & Cyr, J.-F. (2015). Present and future Laurentian Great Lakes hydroclimatic conditions as simulated by regional climate models with an emphasis on Lake Michigan-Huron. Climatic Change, 130(4), 603–618.

Musselman, K. N., Lehner, F., Ikeda, K., Clark, M. P., Prein, A. F., Liu, C., Barlage, M., & Rasmussen, R. (2018). Projected increases and shifts in rain-on-snow flood risk over western North America. Nature Climate Change, 8(9), 808–812.

Na, W., & Najafi, M. R. (2024). Rising risks of hydroclimatic swings: A large ensemble study of dry and wet spell transitions in North America. Global and Planetary Change, 238, 104476.

Negm, A., Abdrakhimova, P., Hayashi, M., & Rasouli, K. (2021). Effects of climate change on depression‐focused groundwater recharge in the Canadian Prairies. Vadose Zone Journal, 20(5), e20153.

New Brunswick Disaster Financial Assistance Program. (2025). New Brunswick Disaster Financial Assistance Program: (PDF).

Niggli, L., Huggel, C., Muccione, V., Neukom, R., & Salzmann, N. (2022). Towards improved understanding of cascading and interconnected risks from concurrent weather extremes: Analysis of historical heat and drought extreme events. PLoS Climate, 1(8), Article 8.

NOAA. (2024). The Great Lakes water level dashboard. National Oceanographic and Atmospheric Agency (NOAA) - Great Lakes Environmental Research Laboratory.

Nolin, A. F., Girardin, M. P., Adamowski, J. F., Barzegar, R., Boucher, M.-A., Tardif, J. C., & Bergeron, Y. (2023). Observed and projected trends in spring flood discharges for the Upper Harricana River, eastern boreal Canada. Journal of Hydrology: Regional Studies, 48, 101462.

Nummelin, A., Ilicak, M., Li, C., & Smedsrud, L. H. (2016). Consequences of future increased Arctic runoff on Arctic Ocean stratification, circulation, and sea ice cover. Journal of Geophysical Research: Oceans, 121(1), 617–637.

Oh, S.-G., & Sushama, L. (2020). Short-duration precipitation extremes over Canada in a warmer climate. Climate Dynamics, 54(3), Article 3–4.

Oki, T., & Kanae, S. (2006). Global hydrological cycles and world water resources. Science, 313(5790), 1068–1072.

Olthof, I., & Rainville, T. (2022). Dynamic surface water maps of Canada from 1984 to 2019 Landsat satellite imagery. Remote Sensing of Environment, 279, 113121.

Oozeer, Y., Fletcher, C. G., & Champagne, C. (2020). Evaluation of satellite-derived surface soil moisture products over agricultural regions of Canada. Remote Sensing, 12(9), 1455.

Orlowsky, B., & Seneviratne, S. I. (2013). Elusive drought: Uncertainty in observed trends and short-and long-term CMIP5 projections. Hydrology and Earth System Sciences, 17(5), 1765–1781.

Oulahen, G. (2015). Flood insurance in Canada: Implications for flood management and residential vulnerability to flood hazards. Environmental Management, 55(3), 603–615.

Pacheco, A., McNairn, H., Mahmoodi, A., Champagne, C., & Kerr, Y. H. (2015). The impact of national land cover and soils data on SMOS soil moisture retrieval over Canadian agricultural landscapes. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 8(11), 5281–5293.

Palmer, W. C. (1965). Meteorological drought (PDF). US Department of Commerce, Weather Bureau.

Park, H., Watanabe, E., Kim, Y., Polyakov, I., Oshima, K., Zhang, X., Kimball, J. S., & Yang, D. (2020). Increasing riverine heat influx triggers Arctic sea ice decline and oceanic and atmospheric warming. Science Advances, 6(45), eabc4699.

Park, H., Yoshikawa, Y., Yang, D., & Oshima, K. (2017). Warming water in Arctic terrestrial rivers under climate change. Journal of Hydrometeorology, 18(7), 1983–1995.

Parmesan, C., Morecroft, M. D., Trisurat, Y., Adrian, R., Anshari, G. Z., Arneth, A., Gao, Q., Gonzalez, P., Harris, R., Price, J., Stevens, N., & Talukdarr, G. H. (2022). Terrestrial and freshwater ecosystems and their services. In H. O. Pörtner, D. C. Roberts, M. Tignor, E. S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, & B. Rama (Eds), Climate change 2022: Impacts, adaptation and vulnerability. Contribution of working group II to the Sixth Assessment Report of the  Intergovernmental Panel on Climate Change (pp. 197–378). Cambridge University Press.

Pereira, L. S., Allen, R. G., Smith, M., & Raes, D. (2015). Crop evapotranspiration estimation with FAO56: Past and future. Agricultural Water Management, 147, 4–20.

Persaud, E., & Levison, J. (2021). Impacts of changing watershed conditions in the assessment of future groundwater contamination risk. Journal of Hydrology, 603, 127142.

Peters, D. L., & Buttle, J. M. (2010). The effects of flow regulation and climatic variability on obstructed drainage and reverse flow contribution in a Northern river–lake–Delta complex, Mackenzie basin headwaters. River Research and Applications, 26(9), 1065–1089.

Peters, D. L., Caissie, D., Monk, W. A., Rood, S. B., & St-Hilaire, A. (2016). An ecological perspective on floods in Canada. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 41(1–2), 288–306.

Peters, D. L., Prowse, T. D., Pietroniro, A., & Leconte, R. (2006). Flood hydrology of the Peace‐Athabasca Delta, northern Canada. Hydrological Processes, 20(19), 4073–4096.

Peters, D. L., Watt, D., Devito, K., Monk, W. A., Shrestha, R. R., & Baird, D. J. (2022). Changes in geographical runoff generation in regions affected by climate and resource development: A case study of the Athabasca River. Journal of Hydrology: Regional Studies, 39, 100981.

Pfahl, S., O’Gorman, P. A., & Fischer, E. M. (2017). Understanding the regional pattern of projected future changes in extreme precipitation. Nature Climate Change, 7(6), Article 6.

Philip, S. Y., Kew, S. F., Van Oldenborgh, G. J., Anslow, F. S., Seneviratne, S. I., Vautard, R., Coumou, D., Ebi, K. L., Arrighi, J., Singh, R., Van Aalst, M., Pereira Marghidan, C., Wehner, M., Yang, W., Li, S., Schumacher, D. L., Hauser, M., Bonnet, R., Luu, L. N., … Otto, F. E. L. (2022). Rapid attribution analysis of the extraordinary heat wave on the Pacific coast of the US and Canada in June 2021. Earth System Dynamics, 13(4), Article 4.

Pierce, D. W., Cayan, D. R., Feldman, D. R., & Risser, M. D. (2023). Future increases in North American extreme precipitation in CMIP6 downscaled with LOCA. Journal of Hydrometeorology, 24(5), 951–975.

Pitt, R., Clark, S., & Field, R. (1999). Groundwater contamination potential from stormwater infiltration practices. Urban Water, 1(3), 217–236.

Pomeroy, J. W., Stewart, R. E., & Whitfield, P. H. (2016). The 2013 flood event in the South Saskatchewan and Elk River basins: Causes, assessment and damagesv. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 41(1–2), Article 1–2.

Pradhananga, D., & Pomeroy, J. W. (2022). Recent hydrological response of glaciers in the Canadian Rockies to changing climate and glacier configuration. Hydrology and Earth System Sciences, 26(10), 2605–2616.

Public Safety Canada. (2022). Adapting to rising flood risk: An analysis of insurance solutions for Canada. A Report by Canada’s Task Force on Flood Insurance and Relocation.

Public Safety Canada. (2025, February 5). About the DFAA.

Qian, B., Zhang, X., Smith, W., Grant, B., Jing, Q., Cannon, A. J., Neilsen, D., McConkey, B., Li, G., Bonsal, B., Wan, H., Xue, L., & Zhao, J. (2019). Climate change impacts on Canadian yields of spring wheat, canola and maize for global warming levels of 1.5 °C, 2.0 °C, 2.5 °C and 3.0 °C. Environmental Research Letters, 14(7), 074005.

Quinton, W. L., Connon, R. F., & Devoie, É. G. (2019). Permafrost monitoring at Scotty Creek Research Station, 2011-2017 [Northwest Territories, Canada] (Version 2) [Data set]. Borealis.

Quiring, S. M., & Papakryiakou, T. N. (2003). An evaluation of agricultural drought indices for the Canadian prairies. Agricultural and Forest Meteorology, 118(1–2), 49–62.

Radić, V., Cannon, A. J., Menounos, B., & Gi, N. (2015). Future changes in autumn atmospheric river events in British Columbia, Canada, as projected by CMIP5 global climate models. Journal of Geophysical Research: Atmospheres, 120(18), 9279–9302.

RahimiMovaghar, M., Fereshtehpour, M., & Najafi, M. R. (2024). Spatiotemporal pattern of successive hydro-hazards and the influence of low-frequency variability modes over Canada. Journal of Hydrology, 634, 131057.

RahimiMovaghar, M., Najafi, M. R., Shrestha, R. R., & Liu, Y. (2025). Successive warm-wet and warm-dry events in the Great Lakes Basin: Future projections using CMIP6 models. Climate Dynamics, 63(1), 80.

Rasmussen, K. L., Prein, A. F., Rasmussen, R. M., Ikeda, K., & Liu, C. (2017). Changes in the convective population and thermodynamic environments in convection-permitting regional climate simulations over the United States. Climate Dynamics, 55(1–2), 383–408.

Rawlins, M. A., & Karmalkar, A. V. (2024). Regime shifts in Arctic terrestrial hydrology manifested from impacts of climate warming. The Cryosphere, 18(3), 1033–1052.

Reich, P. B., Bermudez, R., Montgomery, R. A., Rich, R. L., Rice, K. E., Hobbie, S. E., & Stefanski, A. (2022). Even modest climate change may lead to major transitions in boreal forests. Nature, 608(7923), 540–545.

Rezvani, R., Na, W., & Najafi, M. R. (2023). Lagged compound dry and wet spells in Northwest North America under 1.5 °C–4 °C global warming levels. Atmospheric Research, 290, 106799.

Rezvani, R., RahimiMovaghar, M., Na, W., & Najafi, M. R. (2023). Accelerated lagged compound floods and droughts in northwest North America under 1.5 °C − 4 °C global warming levels. Journal of Hydrology, 624, 129906.

Rivard, C., Vigneault, H., Piggott, A. R., Larocque, M., & Anctil, F. (2009). Groundwater recharge trends in Canada Geological Survey of Canada Contribution 20090009. Canadian Journal of Earth Sciences, 46(11), 841–854.

Rivera, A. (Ed.). (2014). Groundwater Basics. In Canada’s groundwater resources (pp. 23–59). Fitzhenry & Whiteside.

Rokaya, P., Peters, D. L., Elshamy, M., Budhathoki, S., & Lindenschmidt, K.-E. (2020). Impacts of future climate on the hydrology of a northern headwaters basin and its implications for a downstream deltaic ecosystem. Hydrological Processes, 34(7), 1630–1646.

Rousseau-Gueutin, P., Love, A. J., Vasseur, G., Robinson, N. I., Simmons, C. T., & De Marsily, G. (2013). Time to reach near-steady state in large aquifers. Water Resources Research, 49(10), 6893–6908.

Rudolph, D. L., Melchin, J., Stone, M., Sarwar, G., & Hodgins, E. (2023). Efficacy of urban road salt reduction strategies on public supply well quality. Science of The Total Environment, 900, 166466.

Sadri, S., Famiglietti, J. S., Pan, M., Beck, H. E., Berg, A., & Wood, E. F. (2022). FarmCan: A physical, statistical, and machine learning model to forecast crop water deficit for farms. Hydrology and Earth System Sciences, 26(20), 5373–5390.

Sandink, D., & Binns, A. D. (2021). Reducing urban flood risk through building- and lot-scale flood mitigation approaches: Challenges and opportunities. Frontiers in Water, 3, 689202.

Sauchyn, D., & St-Jacques, J.-M. (2016). Science, assessments and data availability related to anticipated climate and hydrologic changes in inland freshwaters of the prairies region (Lake Winnipeg drainage basin) (PDF). Fisheries and Oceans Canada.

Scaff, L., Prein, A. F., Li, Y., Liu, C., Rasmussen, R., & Ikeda, K. (2020). Simulating the convective precipitation diurnal cycle in North America’s current and future climate. Climate Dynamics, 55(1–2), Article 1–2.

Scheepers, H., Wang, J., Gan, T. Y., & Kuo, C. C. (2018). The impact of climate change on inland waterway transport: Effects of low water levels on the Mackenzie River. Journal of Hydrology, 566, 285–298.

Schnorbus, M. A. (2020). VIC glacier (VIC-GL) – Model set-up and deployment for the Peace, Fraser, and Columbia (p. 72) (PDF). Pacific Climate Impacts Consortium.

Schoeneberg, A. T., & Schnorbus, M. A. (2021). Exploring the strength and limitations of PCIC’s CMIP5 hydrologic scenarios (p. 42). Pacific Climate Impacts Consortium.

Seglenieks, F., & Temgoua, A. (2022). Future water levels of the Great Lakes under 1.5 °C to 3 °C warmer climates. Journal of Great Lakes Research, 48, 865–875.

Seneviratne, S. I., Nicholls, N., Easterling, D., Goodess, C., Kanae, S., Kossin, J., Luo, Y., Marengo, J., McInnes, K., Rahimi, M., Reichstein, M., Sorteberg, A., Vera, C., & Zhang, X. (2012). Changes in climate extremes and their impacts on the natural physical environment. In Managing the risks of extreme events and disasters to advance climate change adaptation: Special report of the intergovernmental panel on climate change (pp. 109–230). Cambridge University Press.

Seneviratne, S. I., Zhang, X., Adnan, M., Badi, W., Dereczynski, C., Di Luca, A., Ghosh, S., Iskandar, I., Kossin, J., Lewis, S., Otto, F., Pinto, I., Satoh, M., Vicente-Serrano, S. M., Wehner, M., & Zhou, B. (2021). Weather and climate extreme events in a changing climate. In V. Masson-Delmotte, P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, & B. Zhou (Eds), Climate Change 2021: The physical science basis. Contribution of working group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (pp. 1513–1766). Cambridge University Press.

Shah, L., Arnillas, C. A., & Arhonditsis, G. B. (2022). Characterizing temporal trends of meteorological extremes in Southern and Central Ontario, Canada. Weather and Climate Extremes, 35, 100411.

Sheffield, J., Wood, E. F., & Roderick, M. L. (2012). Little change in global drought over the past 60 years. Nature, 491(7424), 435–438.

Shepherd, T. G. (2014). Atmospheric circulation as a source of uncertainty in climate change projections. Nature Geoscience, 7(10), Article 10.

Shrestha, N. K., Seglenieks, F., Temgoua, A. G. T., & Dehghan, A. (2022). The impacts of climate change on land hydroclimatology of the Laurentian Great Lakes basin. Frontiers in Water, 4, 1–22.

Shrestha, R. R., Bonsal, B. R., Bonnyman, J. M., Cannon, A. J., & Najafi, M. R. (2021). Heterogeneous snowpack response and snow drought occurrence across river basins of northwestern North America under 1.0°C to 4.0°C global warming. Climatic Change, 164(3), 40. https://doi.org/10.1007/s10584-021-02968-7

Shrestha, R. R., Bonsal, B. R., Kayastha, A., Dibike, Y. B., & Spence, C. (2021). Snowpack response in the Assiniboine-Red River basin associated with projected global warming of 1.0 °C to 3.0 °C. Journal of Great Lakes Research, 47(3), 677–689.

Shrestha, R. R., Pesklevits, J., Yang, D., Peters, D.L., & Dibike, Y.B. (2021). Climatic controls on mean and extreme streamflow changes across the permafrost region of Canada. Water 13(5): 626,

Shrestha, R. R., Cannon, A. J., Schnorbus, M. A., & Alford, H. (2019). Climatic controls on future hydrologic changes in a Subarctic River basin in Canada. Journal of Hydrometeorology, 20(9), 1757–1778.

Shrestha, R. R., Dibike, Y. B., & Bonsal, B. R. (2022). vSnowpack-driven streamflow predictability under future climate: Contrasting changes across two western Canadian river basins. Journal of Hydrometeorology. https://doi.org/10.1175/JHM-D-21-0214.1

Shrestha, R. R., & Pesklevits, J. C. (2023). Reconstructed river water temperature dataset for western Canada 1980–2018. Data, 8(3), Article 3.

Shrestha, R. R., Pesklevits, J. C., Bonsal, B. R., Brannen, R., Guo, T., & Hoffman, S. (2024). Rising summer river water temperature across Canada: Spatial patterns and hydroclimatic controls. Environmental Research Letters, 19(4), 044058.

Siemens, K., Dibike, Y., Shrestha, R., & Prowse, T. (2021). Runoff projection from an Alpine watershed in western Canada: Application of a snowmelt runoff model. Water, 13(9), 1199.

Smith, A. L., Hewitt, N., Klenk, N., Bazely, D. R., Yan, N., Wood, S., Henriques, I., MacLellan, J. I., & Lipsig-Mummé, C. (2012). Effects of climate change on the distribution of invasive alien species in Canada: A knowledge synthesis of range change projections in a warming world. Environmental Reviews, 20(1), 1–16.

Smith, W., Grant, B., Qi, Z., He, W., Qian, B., Jing, Q., VanderZaag, A., Drury, C. F., St. Luce, M., & Wagner-Riddle, C. (2020). Towards an improved methodology for modelling climate change impacts on cropping systems in cool climates. Science of The Total Environment, 728, 138845.

Smith, W., Grant, B., Qi, Z., He, W., VanderZaag, A., Drury, C. F., Vergè, X., Balde, H., Gordon, R., & Helmers, M. J. (2019). Assessing the impacts of climate variability on fertilizer management decisions for reducing nitrogen losses from corn silage production. Journal of Environmental Quality, 48(4), 1006–1015.

Spence, C., Beaty, K., Blanchfield, P. J., Hrenchuk, L., & MacKay, M. D. (2018). The impact of a loss of hydrologic connectivity on boreal lake thermal and evaporative regimes. Limnology and Oceanography, 63(5), 2028–2044.

Spence, C., & Hedstrom, N. (2018). Hydrometeorological data from Baker Creek Research Watershed, Northwest Territories, Canada. Earth System Science Data, 10(4), 1753–1767.

Spence, C., Norris, M., Bickerton, G., Bonsal, B. R., Brua, R., Culp, J. M., Dibike, Y., Gruber, S., Morse, P. D., Peters, D. L., Shrestha, R., & Wolfe, S. A. (2020). The Canadian water resource vulnerability index to permafrost thaw (CWRVI _PT ). Arctic Science, 6(4), 437–462.

Spence, Christopher., Coles, A., Gibson, J. J., Nicholls, E. M., Perron, N., Sniderhan, A., Sonnentag, O., & Baltzer, J. L. (2024). The influence of tree infilling on energy partitioning, vegetation water use, and soil water state in sparse conifer stands of the taiga shield ecoregion. Water Resources Research, 60(8), e2024WR037454.

Spry, C. M., Kohfeld, K. E., Allen, D. M., Dunkley, D., & Lertzman, K. (2014). Characterizing pineapple express storms in the lower mainland of British Columbia, Canada. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 39(3), 302–323.

Stadnyk, T., Déry, S. J., MacDonald, M., & Koenig, K. (2019). The freshwater system. In Z. Z. Kuzyk & L. M. Candlish (Eds.), From science to policy in the Greater Hudson Bay marine region (pp. 115–155). Arctic Net.

Stadnyk, T., Dow, K., Wazney, L., & Blais, E.-L. (2016). The 2011 flood event in the Red River Basin: Causes, assessment and damages. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 41(1–2), 65–73.

Stadnyk, T., Tefs, A., Broesky, M., Déry, S. J., Myers, P. G., Ridenour, N. A., Koenig, K., Vonderbank, L., & Gustafsson, D. (2021). Changing freshwater contributions to the Arctic: A 90-year trend analysis (1981–2070). Elementa: Science of the Anthropocene, 9(1).

Stadnyk, T., & van der Eerden, J. (2024). Peak flow assessment under a changing climate: Recommendations for the Canadian highway bridge design code (PDF). Canadian Standards Association.

Stanic, S., LeRoux, N. K., Paldor, A., Mohammed, A. A., Michael, H. A., & Kurylyk, B. L. (2024). Saltwater intrusion into a confined island aquifer driven by erosion, changing recharge, sea‐level rise, and coastal flooding. Water Resources Research, 60(1), e2023WR036394.

Stewart, I. T., Cayan, D. R., & Dettinger, M. D. (2005). Changes toward earlier streamflow timing across western North Smerica. Journal of Climate, 18(8), 1136–1155.

Stewart, R. E., Szeto, K. K., Bonsal, B. R., Hanesiak, J. M., Kochtubajda, B., Li, Y., Thériault, J. M., DeBeer, C. M., Tam, B. Y., Li, Z., Liu, Z., Bruneau, J. A., Duplessis, P., Marinier, S., & Matte, D. (2019). Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada – Part 1: Projected climate and meteorology. Hydrology and Earth System Sciences, 23(8), 3437–3455.

Stewart, R. E., Thériault, J. M., & Henson, W.. (2015).On the characteristics of and processes producing winter precipitation types near 0° C. Bulletin of the American Meteorological Society, 96(4), 623–639.

Tam, B., Bonsal, B., Zhang, X., Zhang, Q., & Rong, R. (2023). Assessing potential evapotranspiration methods in future drought projections across Canada. Atmosphere-Ocean, 62(3), 193–205.

Tam, B., Szeto, K., Bonsal, B., Flato, G., Cannon, A. J., & Rong, R. (2019). CMIP5 drought projections in Canada based on the Standardized Precipitation Evapotranspiration Index. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 44(1), 90–107.

Tetlock, E., Toth, B., Berg, A., Rowlandson, T., & Ambadan, J. T. (2019). An 11-year (2007–2017) soil moisture and precipitation dataset from the Kenaston Network in the Brightwater Creek basin, Saskatchewan, Canada. Earth System Science Data, 11(2), 787–796.

Teufel, B., Diro, G. T., Whan, K., Milrad, S. M., Jeong, D. I., Ganji, A., Huziy, O., Winger, K., Gyakum, J. R., De Elia, R., Zwiers, F. W., & Sushama, L. (2017). Investigation of the 2013 Alberta flood from weather and climate perspectives. Climate Dynamics, 48(9–10), Article 9–10.

Teufel, B., Sushama, L., Huziy, O., Diro, G. T., Jeong, D. I., Winger, K., Garnaud, C., De Elia, R., Zwiers, F. W., Matthews, H. D., & Nguyen, V.-T.-V. (2019). Investigation of the mechanisms leading to the 2017 Montreal flood. Climate Dynamics, 52(7–8), Article 7–8.

Thériault, J. M., Leroux, N. R., Tchuem Tchuente, O., & Stewart, R. E. (2023). Characteristics of rain-snow transitions over the Canadian Rockies and their changes in warmer climate conditions. Atmosphere-Ocean, 61(5), 352–367.

Thompson, V., Kennedy-Asser, A. T., Vosper, E., Lo, Y. T. E., Huntingford, C., Andrews, O., Collins, M., Hegerl, G. C., & Mitchell, D. (2022). The 2021 western North America heat wave among the most extreme events ever recorded globally. Science Advances, 8(18), Article 18.

Threndyle, R. E., Jamieson, R. C., Kennedy, G., Lake, C. B., & Kurylyk, B. L. (2022). Future inundation of coastal on-site wastewater treatment systems in a region with pronounced sea-level rise. Journal of Hydrology, 614, 128548.

Travers‐Smith, H. Z., Lantz, T. C., & Fraser, R. H. (2021). Surface water dynamics and rapid lake drainage in the western Canadian Subarctic (1985–2020). Journal of Geophysical Research: Biogeosciences, 126(12), e2021JG006445.

Travers-Smith, H. Z., Lantz, T. C., Fraser, R. H., & Kokelj, S. V. (2022). Changes in surface water dynamics across northwestern Canada are influenced by wildfire and permafrost thaw. Environmental Research Letters, 17(11), 114021.

Trenberth, K. E. (2011). Changes in precipitation with climate change. Climate Research, 47(1), 123–138.

Trenberth, K. E., Dai, A., Rasmussen, R. M., & Parsons, D. B. (2003). The changing character of precipitation. Bulletin of the American Meteorological Society, 84(9), 1205–1218.

Tsuruta, K., & Schnorbus, M. A. (2021). Exploring the operational impacts of climate change and glacier loss in the upper Columbia River Basin, Canada. Hydrological Processes, 35(7), e14253.

Umphlett, N. A., Woloszyn, M., Parker, M. A., Akyuz, F. A., Bergantino, A. R., Brotherson, S., Crow Ghost, D., Downey, M., Edwards, L., Hadwen, T., Hoylman, Z., Jencso, K., Kelley, W., Klein, A., Kluck, D., Longknife, D., Low, K., Mahmood, R., Meehan, M., … Tangen, S. (2023). 2020–2021 drought in the U.S. northern plains and Canadian Prairies: Initial assessment of impacts and response to build resilience during an ongoing drought (PDF). NOAA National Integrated Drought Information System.

Van Huissteden, J., Berrittella, C., Parmentier, F. J. W., Mi, Y., Maximov, T. C., & Dolman, A. J. (2011). Methane emissions from permafrost thaw lakes limited by lake drainage. Nature Climate Change, 1(2), 119–123.

Van Loon, A. F. (2015). Hydrological drought explained. Wiley Interdisciplinary Reviews: Water, 2(4), 359–392.

Van Zuiden, T. M., Chen, M. M., Stefanoff, S., Lopez, L., & Sharma, S. (2016). Projected impacts of climate change on three freshwater fishes and potential novel competitive interactions. Diversity and Distributions, 22(5), 603–614.

Vicente-Serrano, S. M., Beguería, S., & López-Moreno, J. I. (2010). A multiscalar drought index sensitive to global warming: The standardized precipitation evapotranspiration index. Journal of Climate, 23(7), 1696–1718.

Vieira, M. J. F., & Stadnyk, T. (2023). Leveraging global climate models to assess multi-year hydrologic drought. Npj Climate and Atmospheric Science, 6(1), 179.

Wadsworth, E., Champagne, C., & Berg, A. A. (2020). Evaluating the utility of remotely sensed soil moisture for the characterization of runoff response over Canadian watersheds. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 45(1), 77–89.

Walsh, J. E., Ballinger, T. J., Euskirchen, E. S., Hanna, E., Mård, J., Overland, J. E., Tangen, H., & Vihma, T. (2020). Extreme weather and climate events in northern areas: A review. Earth-Science Reviews, 209, 103324.

Wang, H., Liu, J., Klaar, M., Chen, A., Gudmundsson, L., & Holden, J. (2024). Anthropogenic climate change has influenced global river flow seasonality. Science, 383(6686), 1009–1014.

Wang, M., Yang, Q., Overland, J. E., & Stabeno, P. (2018). Sea-ice cover timing in the Pacific Arctic: The present and projections to mid-century by selected CMIP5 models. Deep Sea Research Part II: Topical Studies in Oceanography, 152, 22–34.

Wang, Y., Hogg, E. H., Price, D. T., Edwards, J., & Williamson, T. (2014). Past and projected future changes in moisture conditions in the Canadian Boreal Forest. The Forestry Chronicle, 90(5), Article 5.

Warden, J. W., Rezvani, R., Najafi, M. R., & Shrestha, R. R. (2024). Projections of rain-on-snow events in a sub-arctic river basin under 1.5°C–4°C global warming. Hydrological Processes, 38(8), e15250.

Watt, W. E., Lathem, K. W., & Neill, C. R. (1989). Hydrology of floods in Canada: A guide to planning and design. National Research Council Canada.

Wehner, M. F., Arnold, J. R., Knutson, T., Kunkel, K. E., & LeGrande, A. N. (2017). Ch. 8: Droughts, floods, and wildfires. In D. J. Wuebbles, D. W. Fahey, K. A. Hibbard, D. J. Dokken, B. C. Stewart, & T. K. Maycock (Eds), Climate science special report: Fourth national climate assessment, volume I (pp. 231–256). U.S. Global Change Research Program.

Westra, S., Fowler, H. J., Evans, J. P., Alexander, L. V., Berg, P., Johnson, F., Kendon, E. J., Lenderink, G., & Roberts, N. M. (2014). Future changes to the intensity and frequency of short-duration extreme rainfall: FUTURE INTENSITY OF SUB-DAILY RAINFALL. Reviews of Geophysics, 52(3), 522–555.

Wheaton, E., Bonsal, B., & Sauchyn, D. (2023). Compound extremes of droughts and pluvials: A review and exploration of spatio-temporal characteristics and associated risks in the Canadian Prairies. Water, 15(19), 3509.

White, J., Berg, A. A., Champagne, C., Warland, J., & Zhang, Y. (2019). Canola yield sensitivity to climate indicators and passive microwave-derived soil moisture estimates in Saskatchewan, Canada. Agricultural and Forest Meteorology, 268, 354–362.

White, J., Berg, A. A., Champagne, C., Zhang, Y., Chipanshi, A., & Daneshfar, B. (2020). Improving crop yield forecasts with satellite-based soil moisture estimates: An example for township level canola yield forecasts over the Canadian Prairies. International Journal of Applied Earth Observation and Geoinformation, 89, 102092.

White, R. H., Anderson, S., Booth, J. F., Braich, G., Draeger, C., Fei, C., Harley, C. D. G., Henderson, S. B., Jakob, M., Lau, C.-A., Mareshet Admasu, L., Narinesingh, V., Rodell, C., Roocroft, E., Weinberger, K. R., & West, G. (2023). The unprecedented Pacific Northwest heatwave of June 2021. Nature Communications, 14, 727.

Wilhite, D. A., Sivakumar, M. V., & Pulwarty, R. (2014). Managing drought risk in a changing climate: The role of national drought policy. Weather and Climate Extremes, 3, 4–13.

Woolway, R. I., Huang, L., Sharma, S., Lee, S.-S., Rodgers, K. B., & Timmermann, A. (2022). Lake Ice Will Be Less Safe for Recreation and Transportation Under Future Warming. Earth’s Future, 10(10), e2022EF002907.

Woolway, R. I., Kraemer, B. M., Lenters, J. D., Merchant, C. J., O’Reilly, C. M., & Sharma, S. (2020). Global lake responses to climate change. Nature Reviews Earth & Environment, 1(8), 388–403.

Wu, Y., Liang, Y., Kuo, Y., Lehner, F., Previdi, M., Polvani, L. M., Lo, M., & Lan, C. (2023). Exploiting SMILEs and the CMIP5 archive to understand Arctic climate change seasonality and uncertainty. Geophysical Research Letters, 50(2), e2022GL100745.

Xu, L., Chen, N., & Zhang, X. (2019). Global drought trends under 1.5 and 2 C warming. International Journal of Climatology, 39(4), Article 4.

Yan, H., Sun, N., Fullerton, A., & Baerwalde, M. (2021). Greater vulnerability of snowmelt-fed river thermal regimes to a warming climate. Environmental Research Letters, 16(5), 054006.

Yang, Y., Gan, T. Y., & Tan, X. (2020). Spatiotemporal changes of drought characteristics and their dynamic drivers in Canada. Atmospheric Research, 232, 104695.

Yao, F., Livneh, B., Rajagopalan, B., Wang, J., Crétaux, J.-F., Wada, Y., & Berge-Nguyen, M. (2023). Satellites reveal widespread decline in global lake water storage. Science, 380(6646), 743–749.

Yuan, J., Van Dyke, M. I., & Huck, P. M. (2016). Water reuse through managed aquifer recharge (MAR): Assessment of regulations/guidelines and case studies. Water Quality Research Journal, 51(4), 357–376.

Zaerpour, M., Hatami, S., Sadri, J., & Nazemi, A. (2021). A global algorithm for identifying changing streamflow regimes: Application to Canadian natural streams (1966–2010). Hydrology and Earth System Sciences, 25(9), Article 9.

Zaghloul, M. S., Ghaderpour, E., Dastour, H., Farjad, B., Gupta, A., Eum, H., Achari, G., & Hassan, Q. K. (2022). Long term trend analysis of river flow and climate in northern Canada. Hydrology, 9(11), 197.

Zare, M., Azam, S., Sauchyn, D., & Basu, S. (2023). Assessment of meteorological and agricultural drought indices under climate change scenarios in the south Saskatchewan river basin, Canada. Sustainability, 15(7), 5907.

Zeng, Z., Peng, L., & Piao, S. (2018). Response of terrestrial evapotranspiration to earth’s greening. Current Opinion in Environmental Sustainability, 33, 9–25.

Zhang, S., Gan, T. Y., Bush, A. B. G., & Zhang, G. (2023). Evaluation of the impact of climate change on the streamflow of major pan-Arctic river basins through machine learning models. Journal of Hydrology, 619, 129295.

Zhang, X., Flato, G., Kirchmeier-Young, M., Vincent, L. A., Wan, H., Wang, X. L., Rong, R., Fyfe, J., Li, G., & Kharin, V. V. (2019). Changes in temperature and precipitation across Canada. In E. Bush & D. S. Lemmen (Eds), Canada’s changing climate report (pp. 112–193). Government of Canada.

Zhang, Y., & Fueglistaler, S. (2019). Mechanism for increasing tropical rainfall unevenness with global warming. Geophysical Research Letters, 46(24), 14836–14843.

Zhao, C., Brissette, F., Chen, J., & Martel, J.-L. (2020). Frequency change of future extreme summer meteorological and hydrological droughts over North America. Journal of Hydrology, 584, 124316.

Zhao, G., Li, Y., Zhou, L., & Gao, H. (2022). Evaporative water loss of 1.42 million global lakes. Nature Communications, 13(1), 3686.

Zhao, J., He, S., Wang, H., & Li, F. (2022). Constraining CMIP6 projections of an ice‐free Arctic using a weighting scheme. Earth’s Future, 10(10), e2022EF002708.

Zhao, T., & Dai, A. (2015). The magnitude and causes of global drought changes in the twenty-first century under a low–moderate emissions scenario. Journal of Climate, 28(11), 4490–4512.

Zhao, T., & Dai, A. (2021). CMIP6 model-projected hydroclimatic and drought changes and their causes in the 21st century. Journal of Climate, 35(3), 897–921.

Zheng, L., Nico, P., Spycher, N., Domen, J., & Credoz, A. (2021). Potential impacts of CO₂ leakage on groundwater quality of overlying aquifer at geological carbon sequestration sites: A review and a proposed assessment procedure. Greenhouse Gases: Science and Technology, 11(5), 1134–1166.

Zhou, X., Atlas, R., McCoy, I. L., Bretherton, C. S., Bardeen, C., Gettelman, A., Lin, P., & Ming, Y. (2021). Evaluation of cloud and precipitation simulations in CAM6 and AM4 using observations over the southern ocean. Earth and Space Science, 8(2), e2020EA001241.

Zhou, Y., Vidrio-Sahagún, C. T., Ryan, M. C., & He, J. (2022). Hydrological behaviour of an unregulated eastern slope river under changing historical climate. Canadian Water Resources Journal / Revue Canadienne Des Ressources Hydriques, 47(2–3), 137–153.