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Streams, Lakes, and Dams

A photo of Mirror LakeWater is one of our most precious natural resources.  With more than 100,000 miles of rivers and streams, 360 miles of coastline, and more than 1,400 named lakes, Oregon is renowned for its water.  Surface water is relatively abundant in Oregon, but it is unevenly distributed with respect to location and timing.  Major river systems drain the Coast Range, Cascades, Klamath, Blue, and Wallowa Mountains, and into the terminal lakes in the Great Basin.  Each of these areas has a distinct topography and biology, which interact with climate and geology to produce unique runoff patterns.  Natural and human-made storage also play a major role in our water supplies, especially in the dry summer months. 

The following pages contain information related to our Surface Water Hydrology and Dam Safety programs.