This article, the fourth in a series of updates regarding implementation of the Buffer Law, summarizes six common alternative practices that landowners may wish to consider in lieu of a standard buffer. Read more in Part One: The Law; Part Two: Compliance; and Part Three: Enforcement.
The Buffer Law generally requires affected landowners to install a 50-foot average (30-foot minimum) width buffer of perennial vegetation adjacent to public waters by November 1, 2017, and a 16 ½ foot width buffer of perennial vegetation adjacent to public ditches by November 1, 2018. However, a landowner may meet the requirements of the Buffer Law by adopting an alternative practice that provides comparable water quality protection.(i) The Minnesota Board of Water and Soil Resources (BWSR) recently issued technical guidance regarding six common alternative practices that may satisfy the Buffer Law requirements in certain circumstances. The technical document notes that Landowners may install alternative practices with or without assistance from Soil and Water Conservation Districts (SWCD’s).
The six common alternative practice examples developed by BWSR include:
1. Minnesota Agricultural Water Quality Certification Program: If a parcel is certified under the Minnesota Agricultural Water Quality Certification Program, then it is in compliance under the alternative practices provision of the Buffer Law.(ii)
2. USDA Field Office Technical Guide Practice Standards Filter Strip (393/391) - Public Waters (with 50’ buffer standard). This alternative practice uses Natural Resources Conservation Service Standard 393 (for a filter strip of herbaceous vegetation that removes contaminants from overland flow) or Standard 391 (for a riparian forest buffer adjacent to permanent or intermittent streams, lakes, ponds, and wetlands) to comply with the Minnesota Buffer Law.
3. Grassed Waterway/Cultivated Watercourses - Public Waters (with 50’ average buffer standard). This alternative practice may be appropriate if a watercourse identified on the Buffer Protection Map has no clearly defined bed or bank and has no normal water level. In this case, BWSR’s technical document defines a grassed waterway as “a shaped or graded channel that is established with suitable vegetation to convey surface water at a non-erosive velocity using a broad and shallow cross section to a stable outlet.”
4A. Negative slopes or concentrated inflow - Public Ditches (with 16.5’ buffer standard). This alternative practice may be appropriate if the land slopes away from the top of the channel of a public drainage ditch or there are high areas or berms next to the channel, and if water typically flows into the public ditch through areas of open channel concentrated flows or through an installed pipe or conduit. This practice includes installation of perennial vegetation to help provide bank stability and to serve as a tillage setback plus treatment of all discharge which flows into the waterbody via concentrated flow or other conduit.
4B. Glacial Lake Plain Areas - Public Ditches (with 16.5’ buffer standard). This common alternative practice may be appropriate on Public Ditches in locations where the primary surface runoff contributing area is approximately 0.1% slope, the channel and banks are fully vegetated and stable, and surface water typically enters the public ditch through open channel concentrated flows, or rarely and minimally flows directly over the channel bank into the public ditch. This treats runoff where it enters the ditch.
5. Negative slopes or concentrated inflow - Public Waters (with 50’ buffer standard). This common alternative practice may be appropriate if the land slopes away from the top of the bank of a water body, or there are existing high areas next to the bank which prevent flow from uniformly entering the water body; runoff typically enters the water body through open channel concentrated flows; or runoff typically enters the water body through an installed pipe or conduit. This provides treatment of runoff along the entire frontage of the waterbody.
6. Conservation Tillage/Cover Crops with Vegetated Filter Strip - Public Waters (with 50’ buffer standard). This common alternative practice uses tillage management and/or cover crops in combination with a perennial vegetation filter strip.
BWSR’s technical guidance contains detailed information and diagrams regarding these common alternative practices. The technical document also notes that SWCD’s have the authority and expertise to help landowners determine which alternative practices may be most appropriate for their land and to validate them if requested.
(i) See Minn. Stat. 103F.48, Subd. 3.
(ii) Detailed information regarding the Minnesota Agricultural Water Quality Certification Program is available at http://www.mda.state.mn.us/awqcp.