1. What is a buffer?
A buffer, also known as a riparian area, is land adjacent to a stream, river, lake or wetland. Buffers are critically important to keeping water clean. This buffer strip in southern Minnesota shows a vegetated strip that helps filter pollutants and runoff from entering the water from the surrounding land.

2. What is a buffer?
An example of a vegetated buffer strip in southern Minnesota. The grass strip prevents runoff from reaching a stream on the far left.

3. What is a buffer?
Phosphorus, nitrogen, and sediment are the most common pollutants in Minnesota lakes and rivers, according to the Minnesota Pollution Control Agency. This grass buffer in Redwood County keeps those chemicals from going into this stream.

4. What is a buffer?
An example of a grass buffer in Redwood County that helps filter out pollutants. Many waters in far southwest Minnesota do not meet swimmable, fishable standards.

5. What is a buffer?
The aerial view shows grass buffer strips along a stream in Olmsted County. Without a buffer of plants to filter runoff, pollutants such as sediment and algae-causing nutrients can drain to the water.

6. What is a buffer?
This Olmsted County buffer has a mixture of grass and shrubs. Roots from these plants can absorb polluting nutrients.

7. What is a buffer?
Another aerial view of a grass buffer in southeast Minnesota. Vegetative buffers can help prevent erosion, keeping soil out of streams.

8. What is a buffer?
Another Olmsted County vegetative buffer that is stabilizing the stream bank and helping keep pollutants out of the water.

9. What is a buffer?
The stream on the left has insufficient buffer coverage. Areas circled in red should have a buffer. The stream on the right has sufficient buffer coverage. 50 feet of perennial vegetation borders the entire shoreline.