Minnesota is one of the few states that require landowners to keep a strip of natural vegetation or trees along streams and riverbanks, a tool to protect water from pollution and agricultural runoff. Minnesota’s rule requires a 50-foot buffer of grasses or other natural vegetation between crops and waterways.
The Environmental Working Group, a Washington, D.C., watch-dog group that uses scientific data to influence regulation, mapped cropland in southern Minnesota to determine how many farmers are complying with the law. It found widespread violation of the buffer rule and wide variation among watersheds and counties, which are expected to enforce the rule.
Some officials in Minnesota challenge EWG’s ratings because its analysis included only cropland, not all land, that borders waterways. They say that makes the problem seem worse than it is because other parcels may have better river buffers. EWG says it examined only cropland within 50 feet of waterways because that’s where most of the Midwest’s waterborne pollution comes from. Minnesota regulators have identified agriculture as the primary source of nutrients and soil loss that pollute the Minnesota and Mississippi Rivers, including Lake Pepin.
Click on the map for detailed views and data on the performance of Minnesota counties and watersheds.