The Bull Run River is a major tributary of the Sandy River. The Bull Run River Basin makes up about 25 percent of the 500 square mile Sandy River Basin. Wild populations of steelhead and Chinook have declined 75-90 percent in the Sandy River Basin. The Bull Run water system changed the natural flow of the river, beginning about 100 years ago when the first diversion dam was built. Neither of the Bull Run dams have fish ladders.
Historic habitat is flooded.
Salmon and trout generally favor habitat in wide, flat river valleys. These valleys accumulate gravel for spawning and provide quiet backwaters for resting and feeding. These habitats in the Bull Run watershed were also good locations for constructing dams. Much of the historic habitat above the dams is now flooded by the reservoirs. Flow is reduced.