Soils for Salmon
Hood Canal chum, Puget Sound Chinook salmon and coastal Puget Sound bull trout are currently listed as threatened species in the Puget Sound region. The Soils for Salmon project addresses an aspect of the Endangered Species Act, namely to restore and protect the habitat of these endangered species. The goal is to improve regional soil to reduce the amount of runoff from paved and non-porous surfaces – a large portion of urban areas.
The program achieves its goal by educating a wide range of professionals about the relationship between soils, hydrology and salmon habitat, and promoting techniques to aide salmon recovery efforts through increasing the stormwater, detention and biofiltration capacity of soils that are disturbed by construction.
When new development takes place, the existing vegetation and native soil are removed. After construction, a thin layer of topsoil may be replaced and covered with sod, but the new landscape is compacted and doesn't allow rainwater to infiltrate the soil. Instead, the rainwater runs off into streams, bringing with it sediments and harmful pollutants such as pesticides, fertilizers and animal wastes, and damaging salmon habitat. In addition, streams run "drier" in the summer months because the rainwater is not absorbed into the soil and groundwater, which also hurts fish.
Updated: Dec. 20, 2011