In order to thrive, salmon need clear, cool, clean water. The waterways they inhabit need to be bordered by natural stream side vegetation, and surrounded by healthy flood plains. There must be enough water in rivers and streams at crucial times to allow fish to escape predators, find enough food, and migrate to and from the ocean.
Native stream side vegetation prevents erosion and shades the water so it remains cool. Downed logs and other woody debris store sediment, help to maintain gravel spawning areas, create places for fish to rest and hide, and provide food and nutrients for streams. Flood plains help to maintain steady water flow, absorbing excess water during periods of flooding; otherwise, salmon may be unable to swim or hide in raging currents, or may be carried out of the waterways by rising waters.
Salmon also need to be able to get to and from their spawning grounds. Their habitat should not be obstructed by obstacles or hazards such as dams, culverts, or turbines.