Studies of water quality have shown that non-point source pollution can be greatly reduced by the buffering of streams and rivers by forests and wetlands. When heavily vegetated areas surround surface water bodies, many pollutants are trapped and filtered from the rain water before it reaches the water bodies. Thus, allowing natural areas to recharge aquifers and cleanse storm water potentially saves municipalities millions of dollars in water supply and treatment costs. December 1993 . Trust for Public Land, Sacramento, California.
Open space can save a city millions of dollars in construction costs.
For instance, open space's capacity to absorb stormwater and provide natural drainage means that a preserved system of natural streams can substitute for or supplement extended sewer systems. Also, street trees and parks help reduce glare, clean the air and offset noise pollution. Wetland loss near the port of Redwood City, California is believed to be responsible for damage to shipping channels. Protecting Rivers, Trails, and Greenways Reap Economic Returns. The cleansing and buffer properties of vegetated areas help control water, air, and noise pollution, which may decrease pollution control costs borne by public agencies.