What is a Watershed?

A watershed is an area of land where all water drains to a particular waterbody, usually a stream, river, or the ocean. Watersheds cover the entire land surface of the earth. Watersheds contain homes, neighborhoods, cities, forests, farmland, and more. Watersheds come in all shapes and sizes and can even cross state lines.

The graphic above shows how water travels over a landscape and eventually forms streams and rivers. In a natural environment, this water would be pretty clean; however, when rain hits an impervious surface it creates stormwater runoff, which picks up pollutants and enters the nearest creek or stream. This creek or stream will join others to form larger streams, which join others to flow into larger rivers. Just like streams, smaller watersheds join together to form larger watersheds. That means any pollution that enters our stormwater can transported throughout an entire watershed.

All of us live in a watershed – let’s keep them clean! Use this EPA tool to Surf Your Watershed and find out more about how stormwater, runoff, and streams connect to form watersheds in your area.

How Natural Vegetation Creates Stream Buffers to Protect Waterbodies from Stormwater Pollution (and how you can help build one!)

What is a stream buffer?Image result for riparian buffer

Stream (also called riparian) buffers are strips of trees and other vegetation that:

  • improve water quality by filtering pollutants from stormwater runoff such as oil, fertilizers, pesticides, and dog waste;
  • reduce flooding and erosion by stabilizing stream banks;
  • moderate stream temperature and sunlight, keeping fish and other aquatic life healthy;
  • provide nesting and foraging habitat for many species of birds and animals.

You can help stream buffers purify our water by planting native trees and bushes along your stream or ditch, especially if the bank is bare or eroding. If you already have trees or shrubs along your waterway, simply leave it alone!

Mowing, cutting, and removing buffer vegetation may be regulated in your area, so check with your local government before undertaking landscaping or other projects within 100 feet of any water conveyances. (Selective cutting of understory shrubs and scrub by hand is usually allowed in very small amounts, but it is better to let the vegetation continue its natural regeneration process, which will allow trees to mature, form a canopy, and prevent undergrowth naturally.) Continue reading