Many people like to live near a body of running fresh water. Rivers and streams provide recreation, food, and, of course, drinking water. But when rain or melting snow produces large amounts of water, rivers and streams may flood, causing problems for those who live nearby. Floods endanger the lives of humans and animals and damage property. Bridge abutments, roadways, sewer lines, and other structures within floodways are damaged.
Floods delay traffic and interfere with the economic use of the land.
Navigation and hydroelectric power are often impaired. Spawning grounds for fish and other wildlife habitat are often destroyed. Rapid runoff causes soil erosion as well as sediment deposition downstream. This relatively large population and the development necessary to support it have stressed many of the area s ecological resources. People increase the risk of flooding when they clear trees, remove vegetation from the soil and increase impervious surfaces, thereby decreasing the ability of the soil to absorb the runoff and increasing the volume of water and erosion.