Marmot Dam FERC Project

Columbia River Basin; Sandy River, Multnomah County, Oregon

Project Profile

Prior to removal, Marmot and Little Sandy dams delayed and injured upstream migrating ESA-listed fish. The poorly functioning fish screens drew juveniles into the intake diversion, and low flows limited rearing, spawning, and fish passage.

Listed Species

Lower Columbia River Chinook

Lower Columbia River coho

Lower Columbia River steelhead


Portland General Electric

FERC Relicensing Status

The parties agreed to a settlement in 2002. NOAA Fisheries completed a biological opinion in 2003 for LCR Chinook salmon and LCR coho salmon, and a second opinion in 2007, after listing of LCR coho salmon and designation of critical habitat for LCR Chinook salmon and LCR steelhead.  PGE surrendered the license and removed Marmot Dam in October 2007, and Little Sandy Dam in 2008, improving access to about 90 miles of historical habitat to salmon species.  Removal of the dams is contributing to the recovery of listed species by improving habitat conditions and restoring natural water flow.


Federal Energy Regulatory Commission

FERC eLibrary: Docket #P-477

2003 NOAA Fisheries Biological Opinion

2007 NOAA Fisheries Biological Opinion