What is a watershed?
In the simplest terms, a watershed is an area of land which drains to a central water body such as a river or lake. Also called drainage basins, watersheds range in size from a small retention pond in your neighborhood to the Mississippi River Basin, which transports water from over 30 states to the Gulf of Mexico.
Why are watersheds important?
Examining our communities and the broader region in terms of watersheds can help us make decisions regarding our personal and professional water use. The earth is covered in water - 96.5% is in the oceans, which cover 70% of the earth’s surface. A tiny fraction of earth’s water, only 1.7%, is found in groundwater, rivers, lakes, wetlands, and soils. Groundwater makes up 30% of all freshwater, which is 35 times more water than all the lakes and rivers combined.
So why are we so concerned with surface water if it’s such a small portion of the earth’s tremendous water resource?
The United States has over 4.8 million kilometers of rivers, streams, creeks, and brooks. These bodies of water flow through heavily urbanized cities as well as sparsely populated rural areas and pick up sediment, debris, and other pollutants along the way. Our local stormwater sewer systems (MS4s) contribute water to many streams and creeks as well as the Little Miami River and the Ohio River.
By actively managing the materials discharged into local waterways we can maintain the health of our regional watersheds, thereby providing clean water for creatures and communities downstream.
For more information on watersheds, see the EPA’s Healthy Watersheds Protection FAQ page: https://www.epa.gov/hwp/basic-information-and-answers-frequent-questions