Flood Control by Wetlands

Wetlands slow the flow of water, allowing it to replenish the ground water supply that most plants and many people depend on. By slowing the water during floods, wetlands reduce flood damage in areas downstream and around them. The Environmental Protection Agency (2006, p.1) estimates flood damages in the U.S. average over $2 billion a year. Wetlands play a role in reducing the frequency and intensity of flooding by storing water from storm surges. This also reduces erosion, a particular problem in urban and agricultural areas. Wetlands can be seen as an insurance policy that provides recreation and other benefits, while protecting those who live in low lying areas from floods. “The bottomland hardwood – riparian wetlands along the Mississippi River once stored at least 60 days of flood water. Now they store only 12 days because most have been filled or drained.” (Environmental Protection Agency http://www.epa.gov/owow/wetlands/vital/people.html, Flood Protection, p.2) The Minnesota Department of Natural Resources computed in 1991 a cost of $300 to replace an acre of wetland that holds a foot of water during a storm. (Environmental Protection Agency http://www.epa.gov/OWOW/wetlands/facts/fact4.html, p.2) Destroying wetlands may provide short term economic gain, but long term cost in damage to property, displaced residents and loss of life.