Assessment of Riparian Buffers in the Whitewater River Watershed

Overall Project Outcome and Results
Riparian buffers can provide significant water quality benefits by filtering contaminants such as nitrate, phosphorus, sediment, and pesticides from surface runoff. In addition, buffers stabilize streambanks, enhance riparian and in-stream habitat, and provide landscape connectivity. The DNR's Shoreland Rule requires that landowners maintain a 50 foot buffer of perennial vegetation on public waters. According to previous BWSR estimates, 50% or more of the buffer area in some counties was cropped. Local officials have often struggled to increase compliance with the buffer rule because they did not know the extent and locations of un-buffered streams. This project eliminated that barrier by mapping land use along all public waters in the ten county region of Southeast Minnesota.

Mapping
The Whitewater River Watershed Project contracted with Cannon River Watershed Partnership to produce the maps. The mapping process utilized aerial photography and a Geographic Information System (GIS) to conduct an assessment and analysis of existing stream courses, channels and land use within shoreland areas. The assessment included all perennial streams within the 10-county region and utilized post flood aerial photos where available. Land cover adjacent to protected waters in all participating counties was also identified based on aerial photo interpretation.

From this assessment and analysis, two GIS shapefiles were created for each county: a retraced stream layer and a shoreland layer, which maps the land use within 300 feet of the center line of streams.

A total of 3,800 linear miles of streams were mapped, equaling 430 square miles of buffer area. Approximately 60,000 individual polygons were traced, representing 40 unique land uses. These detailed maps show that a much smaller area is being cropped than previously estimated. All counties had 50 foot buffers on at least 90% of their streams.

All GIS files are available to the public on the CRWP website. However, some experience with GIS is necessary to successfully utilize this data. For non-GIS users, contacting your County for maps they have produced using this data will be more efficient.

Surveys and Focus Groups
In addition to mapping shoreland land use, the project also conducted landowner surveys and focus groups to 1) explore the barriers to buffer adoption, 2) identify opportunities for establishing and maintaining buffers, and 3) explore what actions would increase adoption of these buffers. Reports summarizing the survey and focus group results are available.

Many counties are moving forward to address areas that lack shoreland buffers. Goodhue is implementing a "Hayable Buffer" program, Olmsted has sent out letters to landowners that are out of compliance, Winona is developing a buffer plan, and additional counties are making progress to ensure all streams are protected by perennial buffers.

Project Results Use and Dissemination
The results of the mapping, surveys, and focus groups were presented and discussed at regional meetings including the Basin Alliance of the Lower Mississippi in Minnesota, the Southeast Water Resources Board, and the Southeast Minnesota Association of County Planning and Zoning Administrators. The maps and land use summary statistics are available on the CRWP website (http://www.crwp.net/Programs/Conservation/ShorelandMapping/ShorelandMapping.html). The project was discussed in a July 8th, 2010 article in AgriNews, a newspaper that reaches many farmers in Southeast Minnesota.

In addition to county staff and commissioners, others are using the data for a variety of purposes related to water quality. Minnesota Pollution Control Agency staff is using the maps to help identify stressors to the ecology of streams in the Root River Watershed, and the Fillmore SWCD is using the data to help identify gullies in pastures adjacent to streams. The data can also be used to assess habitat connectivity.