Stream erosion is caused by stormwater swiftly carried to waterways during rain events. When stormwater is routed through pipes to nearby streams and rivers, it picks up speed. As a result, the stormwater entering streams from drainage pipes scours away the stream beds and erodes the stream banks.
Stream bank erosion causes stream beds to deepen over time, which causes further instability in the stream system. All this erosion adds sediment to the water, which has devastating effects on stream ecosystems. Sediment buries aquatic insect life and suffocates fish. Sediment also carries other harmful pollutants such as phosphorous that further worsen aquatic conditions for fish and other wildlife.