The High Water Marks of Flooding

People have always been frightened of floods, and with good reason. Floods are one of the most costly and common natural disturbances in the United States. Although flooding can be devastating to an ill-equipped community, flooding is a natural event with many benefits and is critical in maintaining the health of some ecosystems.

Floodwaters preserve a vital relationship between rivers and the landscape through which they flow. Whenever a river overflows its banks, it deposits sediments, organic matter, and other debris that it has carried downstream onto the adjacent land. After the flood waters descend, the soil is more fertile from organic matter and minerals that were left behind. Since the time of the ancient Egyptians, farmers have known about the benefits of floods. In fact, ancient Egyptians planned their farming lifestyle around the regular flooding of the Nile, learning that the higher the flood, the better that year's harvest would be.

Naturally occurring floodwaters not only replenish agricultural soils with nutrients, but they can provide important habitat for fish, waterfowl and wildlife while helping to maintain high plant diversity. Spring floods submerge wetlands, creating vital spawning and nursery sites for various fish species, as well as food sources for migrating waterfowl. Growing vegetation is able to take advantage of increased light and resources that are available as old vegetation is washed away, while the floodwater helps disperse and germinate seeds. In addition, floodwaters are important to downstream ecology because they transport sediment that is necessary to maintain downstream delta and coastal ecosystems.

Because flooding establishes and fosters much more diverse and complex habitats than when floodwaters are controlled, it is best to embrace good flood plain management to help maintain and encourage the natural benefits of flooding. In other words, it is clear that we should work with the forces of nature instead of attempting to eliminate them. Good land use practices and planning, such as avoiding development on floodplains, help to prevent structural damages from floods. Permitting rivers and streams to overflow their banks naturally is one way to prevent severe flooding downstream. Restoration of forested landscapes, riparian zones and wetland habitats are also great ways to naturally manage floods.

Former WPC intern, Erica Maynard, took today's picture of a flood on French Creek.

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