How will climate change affect Northwest water? PART ONE OF FIVE In the series: climate impacts in the northwest

Climate change will alter patterns of snowfall, rain and snowmelt, shifting how our region receives and stores water. These changes will have an impact on every aspect of life in the Northwest, from forests to farms, ski areas to cities.

Mountain snowpack is nature's water bottle – storing water for summer when there is less rain. Snowmelt from Northwest mountains provides water for drinking, hydropower, fish and more.

Warmer winters will mean less snowfall and earlier snowmelt in the mountains.

Snow melting earlier in the spring will lead to earlier spring flows, meaning a stream that typically was at its peak water level in May or June may see peak streamflows in April or May in the coming decades.

Summer precipitation is likely to decrease.

Most climate models suggest that we should expect less rain in summer. The results are more mixed for other seasons, but generally suggest slightly more rain in fall, winter and spring.

Decreased snowpack, earlier snowmelt and decreasing summer precipitation mean less water will be naturally available in the summer, when we need it most.

Photo credit Kendra Kaiser

Higher river flows as well as heavier rainfall could increase flood risk, particularly in the fall and winter.

What does this mean for the Northwest?

Increased water in winter could lead to:

Water shortages

Reduced water available for growing crops

Reduced hydropower production in summer and fall

Conflicts over water resources

Threats to salmon populations

Declines in drinking water quality

Increased flooding in winter could lead to:

River flooding

More erosion and landslides

Costly stormwater management and flood protection

Threats to salmon populations

The impacts of climate change on water availability and flooding are daunting, but there is a lot we can do to prepare. For example, when roads or culverts are updated due to damage or for regular maintenance, we can incorporate projections of future precipitation into their design to better accommodate future heavy rains and snowmelt.

How are communities preparing for climate impacts on water?

How will climate change affect Northwest forests?

Appreciate

Credits:

Created with images by Markus Gjengaar - "A visit to the summit of Mt. Rainier" • Nathan Dumlao - "untitled image"