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Three-Zone Buffer System | Cost Considerations | Buffer Regulations

Buffers, or protective areas, are important tools that help protect and improve the condition of our waterways. They are often not effective alone, but can be an important part of an overall stormwater management plan. Municipalities may consider adoption of an ordinance that requires creation or maintenance of buffers along streams whether in urban or rural areas. New and existing buffer ordinances should be reviewed for conformance with the minimum standards outlined in NR 151 and should ensure appropriate enforcement of the regulation.

The ordinance may also contain an information and education element to inform the public on the importance of buffers in stormwater management and stream preservation. The WDNR, SEWRPC, and local land and water conservation boards use standards developed by the Natural Resource Conservation Service (NRCS) to establish buffer zones. More information on these standards can be found at the NRCS Web site (www.nrcs.usda.gov/). The Center for Watershed Protection also has a model ordinance that may be used as a starting point to develop a local buffer ordinance (www.cwp.org).

An aquatic or riparian buffer is an area along a waterway or waterbody where development is prohibited or limited. (1) This area helps reduce the potential for pollutants such as sediments and nutrients from reaching the waterway. A forested buffer along a streambed also helps promote bank stability and helps control water temperatures. (2)

It is important to note that a buffer alone cannot treat all stormwater generated by a watershed. Their effectiveness is dependent on their width, type of vegetation, and pollutant load in the stormwater runoff. In the past, establishment of buffer widths had been site specific.

However, the WDNR has developed new regulations for minimum buffer requirements (NR 151):

--- Buffers are only required under the non-agricultural portion of NR 151, specifically the post-construction performance standards. These standards apply only in areas of new development or redevelopment – not agricultural or developed urban areas.

--- 75 feet for wetlands and streams in areas of special natural resource interest (high quality wetlands, and wetlands that are home to endangered species – defined in NR 103.04);

--- 50 feet for wetlands and streams that are highly susceptible to runoff contamination (fens, sedge meadows, bogs, low prairies, conifer swamps, shrub swamps, other forested wetlands, fresh wet meadows, shallow marshes, deep marshes and seasonally flooded basins);

--- 10 percent of the average wetland width, but no less than 10 feet nor more than 30 feet for less susceptible wetlands, which includes degraded wetlands dominated by invasive species such as reed canary grass.

The entire rule can be found by following the link here.

Buffers tend to be more effective in improving the quality of stormwater runoff from rural areas than urban areas. This is primarily due to the difference in the way stormwater runs off the ground surface in the two areas. Runoff from urban areas quickly concentrates into shallow channels because sheet flow conditions cannot be maintained for much more than 75 feet over impervious surfaces. Rural areas can maintain sheet flow between 150 and 300 feet before changing to concentrated flow, allowing the buffer to be more effective. This slower flow allows buffers in rural areas to be more effective. (4)

Three-Zone Buffer System -- Back to Top
The Center for Watershed Protection (CWP) has developed the three-zone buffer system, which breaks down the buffer into three zones: streamside, middle core, and outer zone.

The purpose for each zone is different and therefore they are comprised of different vegetation and have different widths. According to the CWP, the minimum width for a stream buffer is recommended as 100 feet to provide adequate protection (4).

Cost Considerations -- Back to Top
It has been argued that buffers reduce the amount of prime waterfront property available and therefore have a negative impact on the tax base. (5) This argument is not entirely accurate because the presence of a well-established buffer may increase the value of property, which may offset any lost revenue from development. In addition, buffers may be within floodplains or wetland areas, and development within them is already limited by underlying zoning requirements.

In the case where there is a loss of development land, communities may provide density bonuses. These development bonuses are also utilized for open space protection and setbacks requirements. Efficient land use decisions during the land-use planning process and tools such as density bonuses can minimize conflicts between developable land and buffer requirements.

Buffer Regulations -- Back to Top
For more information on Wisconsin Buffer Regulations, follow the link here.

Source for text in oval:
Center for Watershed Protection website, "Aquatic Buffers"

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