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Wetland Functions: Wetlands provide many functions that are valued by people. These functions (and their values) include: surface water storage (flood control), shoreline stabilization (wave damage protection/shoreline erosion control), stream flow maintenance (maintaining aquatic habitat and aesthetic appreciation opportunities), groundwater recharge (some types replenish water supplies), sediment removal and nutrient cycling (water quality protection), supporting aquatic productivity (fishing, shell fishing, and waterfowl hunting), production of trees (timber harvest), production of herbaceous growth (livestock grazing and haying), production of peaty soils (peat harvest), and provision of plant and wildlife habitat (hunting, trapping, plant/wildlife/nature photography, nature observation, and aesthetics). Destruction of wetlands eliminates or severely minimizes their functions and values. Drainage of wetlands prevents surface water storage and reduces their water quality enhancement function, while accelerating the flow of water downstream which may cause increased flood damages. Wetland filling does likewise as well as destroying vital habitats for native fish and wildlife species. The vast majority of wetland benefits accrue to the general public which makes it important to conserve these valuable natural resources. More...http://www.fws.gov/northeast/Wetlands/ Wetlands function as natural sponges that trap and slowly release surface water, rain, snow melt, groundwater and flood waters. Trees, root mats, and other wetland vegetation also slow flood waters and distribute them over the floodplain. This combined water storage and braking can lower flood heights and reduce erosion. Wetlands in and downstream of urban areas counteract the increased rate and volume of surface-water runoff from pavement and buildings. The holding capacity of wetlands help reduce floods and prevents water logging of crops. Preserving and restoring wetlands, together with other water retention, can help or supplant flood control otherwise provided by expensive dredge operations and levees. For example, the bottomland hardwood-riparian wetlands along the Mississippi River once stored at least 60 days of floodwater. Now they store only 12 days because most have been filled or drained. Reference: U.S. Environmental Protection Agency. 1995b. America's wetlands: Our vital link between land and water. Office of Water, Office of Wetlands, Oceans and Watersheds. EPA843-K-95-001. The ability of wetlands to help curtail erosion is so valuable that some states are restoring wetlands in coastal areas to buffer the storm surges from hurricanes and tropical storms. Wetlands at the margins of lakes, rivers, bays, and the ocean protect shorelines and stream banks against erosion. Wetland plants hold the soil in place with their roots, absorb the energy of waves, and break up the flow of stream or river currents. |