Between Land & Water: Buffers for Healthy Streams

The Minnesota Buffer Law was put into law in 2015 to promote healthy bodies of water in Minnesota. Perennial vegetative buffers have been shown to improve many different aspects of water quality. Buffers, also known as riparian filter strips, aid in filtering out nutrients and sediment from runoff, as well as provide bank stability and habitat for aquatic life.

Within Rice County, properties with public waters adjacent to their land are monitored and reviewed by Rice SWCD staff every three years for buffer width requirements. The buffer compliance standards are set by the Board to Water and Soil Resources. For public ditch systems, the buffer width requirement is 16.5 ft, and DNR public waters require a 50-foot average, 30-foot minimum.

An established buffer adjacent to County Ditch 4 in Rice County.

It is important to be mindful of our impacts on the land and to have established buffer strips for properties adjacent to public watercourses. Unfiltered runoff causes excess nutrients to enter our bodies of water, leading to eutrophication, or an overproductive water system. When nutrient levels become excessive, algal blooms form, reducing dissolved oxygen and negatively affecting aquatic life and the health of the water system.

Buffers also impact bank stability by preventing soil loss, additional runoff issues, property damage, and overall degradation of the land’s soil health. Having a stable bank also provides habitat for aquatic life, such as shelter and breeding grounds for fish, birds, and other wildlife.

The Minnesota Pollution Control Agency (MPCA) reported on collected data regarding stream health and buffer quality in 2015. They found that in streams with the majority of the buffer intact, the water quality, bank stability, and macroinvertebrate species were significantly better than in streams where the buffers were not established and intact. When performing their stream surveys, the MPCA used the Index of Biological Integrity (IBI) to determine where on the index scale the quality of the stream fell. The higher the index score, the higher the quality of the stream. For example, Caddisflies and Dragonfly larvae are more sensitive to pollution and will typically be found in higher quality streams. Meanwhile, leeches, black fly larvae, and snails are more tolerant of pollution and can be found in streams that may be more degraded. 

Buffer quality compared to the health of the fish and invertebrate communities for more than 3,500 monitoring sites. Figure taken from the MPCA report on buffers improving water quality (2015).

In 2024, the DNR announced that they would be conducting surveys to begin the process of redetermining the public waters inventory in Minnesota over the next several years. The DNR recently shared the first four counties, and the order of counties will be processed in a quasi-alphabetical order. This process will begin this year, and they are projecting to have twelve counties completed a year for the next eight years. There are several phases to this process as the project continues; you can find more information, subscribe for updates, and track the progress of this project on the MN DNR website under the “Public Waters Inventory Update Project.”

The DNR Public Water Inventory Update Project will be making adjustments to designated public waters. If you have a watercourse adjacent to your property, these updates may be relevant to you. To learn more and stay informed, please reach out to Rice SWCD at 507-332-5408, subscribe to updates on the DNR website, or send an email to the Public Water Inventory Update email address: pwi.update.dnr@state.mn.us.

Allison “Al” Henderson is a Resource Specialist with the Rice Soil & Water Conservation District. She assists landowners the Wetland Conservation Act and buffer strip implementation in Rice County.  Contact Al with your wetland and buffer questions at 507-332-5408.