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1. Retention Ponds

2. What Is It?
A retention basin is used to manage storm water runoff to
prevent flooding and downstream erosion, and improve
water quality in an adjacent river, stream, lake or bay.
Sometimes called a wet pond or wet detention basin, it is
an artificial lake with vegetation around the perimeter, and
includes a permanent pool of water in its design.

3. How Does It Work?
● The basic idea is very simple. Instead of letting runoff from
a building flow straight into a creek, it first flows into the
retention pond. This pond can be either wet or dry. A wet
pond always has some water in it, and therefore looks like
a pond all the time. A dry retention structure may be as
simple as a grassy basin that fills when it rains and then
dries out.
● The point of the retention pond is to let water settle and
absorb into the earth, rather than building up in lakes and
rivers, which causes flooding.

4. How Easy or Complicated Is This?
● It's super easy! A retention pond is formed
naturally based on the slope of the earth near a
structure (i.e. school, apartment complex,
shopping center).
● Next time you are near such a structure, look
around for an area that appears to be where
water runoff goes.

5. Examples

6. Sources
http://en.wikipedia.org/wiki/Retention_basin
http://www.wisegeek.com/what-is-a-retention-
pond.htm
http://www.jewishworldreview.com/1108/HowStu
ffWorks_retention_pond.php3