Fish Need Clean, Abundant Water

Lowlands east of the Cascade Mountains average only about 8 inches of rain a year. The ridgetops and high-elevation forests are largely intact and the snow collected there is the main source of cool, clean water for rivers, especially in the summer. Making sure this water stays clean and abundant for fish downstream is one of the priorities in this region. Several streams have water too warm for fish and some have drastically low flows caused by withdrawals for farmland irrigation. Regional trends indicate that low summer flows will continue to be a challenge.

Water availability, especially during the late summer, affects salmon populations in the region. One way to increase the amount of water in streams in the late summer is to ensure sufficient capture and storage of mountain snowpack. The Upper Columbia Salmon Recovery Board has developed an application called Snow2flow to identify both how forest restoration affects downstream flows and where to target upstream restoration work.

View data on Water statewide. Visit the Salmon Data Hub for more of the data behind the indicator charts and graphs used throughout this site.