Areas east of the Cascade Mountains average only about 8 inches of rain a year. Our ridgetops and high-elevation forests are largely intact, and are the primary source of snowpack, which feeds cool, clean water to our rivers, especially during the summer. Making sure this water stays clean and abundant for fish downstream is one of the priorities in the upper Columbia. Several streams are listed as impaired because the water is too warm and some areas experience drastically low flows in the summer when water is withdrawn to irrigate farms. The trends in the region during the past several decades indicate that low summer flow will continue to be a challenge in the region.
WATER QUALITY INDEX – CLICK >> TO OPEN LEGEND
WATER QUANTITY – CLICK >> TO OPEN LEGEND