Minnesota Buffer Law

When is the “one rod” ditch buffer required on a county ditch?”
All new ditches require a ditch “buffer”.  A buffer is a strip of perennial vegetation (i.e. grass, hay, etc.) that is put in place to help prevent erosion, provide access to maintenance equipment, and also to try to filter “runoff” before it goes into the open ditch waterway.  “One Rod” refers to a 16 ½ foot measurement.  Minnesota State Statutes require a one rod (16 ½ ft.) grass strip on each side of a county drainage ditch.  Existing county drainage systems were essentially grandfathered in, meaning they were allowed to continue without a one-rod buffer until the Drainage Authority ordered a Re-Determination of Benefits, or a Determination of Benefits for an improvement was performed. But in 2015, the Minnesota State legislature passed a bill, and signed by Governor Dayton, that required those grandfathered ditch systems to establish a grass buffer strip by November of 2018.  Ditch buffers are required on all Drainage Improvement projects. Establishing ditch buffers is not required for most repairs. Some repairs, such as re-sloping, require viewers and in those cases a buffer must be established if it wasn’t already.

See the illustration below for how to properly measure your buffer strip.
buffer law
buffer law

Where are buffer strips required?

  • Public waters (lakes, rivers and streams) require a 50-foot buffer strip
  • County drainage ditches require a 16.5-foot buffer strip

A map showing the inventory of MN Public Waters where a 50-foot buffer is required, and the County Drainage Systems where a 16.5-foot buffer is required, can be viewed on the MN Department of Natural Resources page.

Minnesota DNR Buffer Map

**Please remember to keep your buffer strips free of debris, rocks, machinery, or anything else that will cause an obstruction to access for inspection and construction work.