Many of civilization's contaminants are transported in stormwater runoff, which can enter and pollute streams, lakes, wetlands, and ground water. Increase in the volume and rate of stormwater discharges results in more frequent flooding and accelerated erosion of stream channels. Sediment, excess soil nutrients, and toxic substances can destroy fish habitat, decrease recreational and property values, and reduce water's potential as a drinking water source. The end result includes additional tax-dollar remediation of these effects of nonpoint source pollution. Sediment by weight is the largest single pollutant in the United States.
Sediment reduces the productivity of aquatic plant and animal communities.
It can threaten the survival of fish by covering essential spawning grounds, covering eggs, and preventing emergence of recently hatched fish. Sedimentation is a major cause of the decreased quality of fisheries throughout the United States. USDA,Chesapeake Bay Riparian Handbook.