Restoring Rivers by Restoring Flooding
In muddy, raging floodwaters they see regeneration and growth. They see fish migrating and spawning, wetland plants and floodplain forests regenerating, aquatic habitats being formed and reshaped, and essential nutrients being carried into coastal estuaries during floods to nourish food chains and fisheries.
Floodplains and estuaries are the most productive ecosystems on Earth but their health and productivity depend entirely upon a good flood every now and then.
The more than 50,000 large dams built on the world’s rivers have been quite effective in dampening or completely eliminating all but the biggest floods. The aquatic life in dammed rivers has suffered greatly. Nearly 40% of US fish species are imperiled or extinct, and dams are a leading cause.
That’s why the Corps of Engineers, historically the biggest dam-builder in the U.S., is now in the business of making floods. They do it by intentionally releasing large volumes of water from their dams at specific times of the year to reinvigorate river ecosystems in a carefully controlled manner that promises maximum ecological benefit while avoiding damage to structures, roads, and farms.