If one part of the system is affected, other parts are also affected. The value of a wetland cannot be precisely evaluated. It will differ from one area to the next and from one time to another. Readily apparent values of wetlands include their importance as nesting grounds for waterfowl, as spawning grounds for commercial fish and as nurseries for countless numbers of plant species. Other values which are not so readily seen include flood protection, erosion control, underground water recharge, water quality control and the supply of nutrients.
Water is forced down a narrow channel until it reaches a point where it can spread out.
Many cities have already experienced the devastating results of eliminating the land's ability to store excess water. This in turn creates another problem. Soil erosion intensifies with the increasing pace of the water. Rich top soil picked up by the water no longer spreads out along flood plains. Wetlands are also tremendous purifying basins, according to Weller.