Floodplain

Panorama of water within and heading to the floodplains.

"The plants in a floodplain slow the floodwaters and prevent much damage downstream. The deep clay soils here store water, reducing flooding. Without intact floodplains, rivers, streams, and the land around them suffer increased erosion and more damaging floods."

Simply put, a floodplain is an area of land prone to flooding. It is often flat with higher elevation on both sides and may be either very small or very large. While it can be a problem for houses build on floodplains, they play an extremely important role. The floods that occur carry sediment rich in nutrients past banks and into surrounding areas. This in turn makes for fertile land ripe for agriculture and is where some of the world's earliest civilizations arose.

Rather than be labeled as an aquatic or terrestrial ecosystem, some ecologist label floodplains as "pulsed" ecosystems - an intermediate habitat. With exception to extreme events, the "pulse" and reach of a floodplain can be predicted. The flat, fertile, predictable land is therefore considered ideal for building, but often at the cost of the health of the floodplain.

There are six criteria used to determine floodplain health:
1. The ecosystem supports habitats and viable native animal and plant populations similar to those present prior to any disturbances.
2. The ecosystem is able to return to its pre-existing condition after a disturbance, whether natural or human-induced.
3. The ecosystem is able to sustain itself.
4. The river can function as part of a healthy basin.
5. The annual flood pulse "connects" the main channel to its floodplain.
6. Infrequent natural events - floods and droughts - are able to maintain ecological structure and processes within the reach.

A healthy floodplain results in a healthy river. It is also important to understand when developing on a floodplain. Otherwise the result benefits no one.


This is a straight copy-and-paste from my post a few weeks back on Google+ which can be found here along with many, many more photos of the actual floodplain and damage at that time. The photos are from a week before even more, worse flooding. Those photos might come later as the area is currently underwater and unavailable for photographing.