Bluff Standards Update
The Lower Minnesota River Watershed District (LMRWD) updated its Watershed Management Plan in October 2018. By State Statute, this update occurs every 10 years and local governments must comply with newly adopted standards. Among the many updates to the Plan, the District established new standards related to land-disturbing activity along the Minnesota River Bluffs and other steep slope areas within the District. To align the City and Watershed District requirements, the City intends to update its Bluff Protection Overlay Districts and related Code Sections.
The map above allows users to identify the extents of the Lower Minnesota River Watershed District’s new bluff standard (orange) in comparison with the City of Bloomington's existing bluff protection overlay districts (transparent blue). This map can be displayed in 3D by clicking and holding the right mouse button (or using 2 fingers while navigating on a mobile device).
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Steep Slopes Area
While many of the Watershed District's standards are consistent with Bloomington’s practices, a few amendments to the City Code are needed to ensure consistency. Significant attention has been focused on standards for protecting steep slopes along the Minnesota River Valley from soil erosion. Bloomington has long taken steps to protect the bluffs along the river. In 1982, the City adopted the Bluff Report District Plan, which provided the research and rationale for adoption of Bluff Protection Overlay (BPO) Zoning Districts that same year. These districts protect areas situated between the 722 and 800 foot elevation lines along the River Valley bluff.
The updated Watershed District Plan protects steep slope areas that have an average slope of 18 percent or greater measured over a horizontal distance of 25 feet or more, without referencing elevation lines. This revised definition more accurately identifies areas with steep gradients, but the protected area varies from the City’s BPO District boundaries.
Areas identified as having steep slopes by LMRWD's definition are subject to the standards in the following attachment LMRWD_Standards_Excerpt (Steep Slopes).pdf once the Code is amended (by April 2020 at latest).
Study meetings (which members of the public may attend, but no testimony is taken) were held on the following dates:
- May 9th - Planning Commission
- May 14th - Sustainability Commission
- July 8th - City Council
The staff report and documents from the July 8th study item are available at the following webpage (page 5 of the staff report provides a simplified version of the steep slopes and bluff protection standards): https://agendasuite.org/iip/bloomington/agendaitem/details/7151
Informational meetings are open to the public, and will be scheduled in early 2020. Dates will be posted here once final. To be notified of updates, please enter your email in the E-Subscribe box on the right.
Public Hearings are anticipated by April 2020 at latest.
Lower Minnesota River Watershed District (LMRWD) Resources
The full Watershed Management Plan can be viewed at the District's webpage:
Updated standards are found in the Plan's Appendices:
Please note that the Lower Minnesota River Watershed District is fully independent of the City of Bloomington.
Best Practices along the Bluff
Minimize stormwater runoff down the bluff
- Consider maintaining an unmowed strip of land, 10 to 20 feet, from the top of steep slopes; let deep-rooted vegetation anchor the top of the bluff slope and the bluff itself
- Minimize impervious (paved) surfaces and mowed lawn area
- Direct runoff from paved surfaces into vegetated areas
- Direct runoff away from the bluff edge to prevent soil erosion
Manage soil erosion
- Stabilize bare slopes
- Be careful when removing invasive species, which may leave soils bare and prone to erosion
- Cover bare soils with biodegradable erosion control blankets and/or logs
- Plant bare areas with seedlings or seeds of native species and mulch
Maintain a Healthy, Native Bluff Environment
- Properly dispose of yard waste, including grass clippings, leaves, twigs, and pet waste (Not over the bluff)
- Clippings may contain chemicals that wash off into the waterways
- Clippings also decompose and release nutrients, such as nitrogen, which attracts invasive species
- Piled yard waste, when left to sit, kills the underlying vegetation. This exposes those soils, and makes them more susceptible to erosion.
- Consider planting native species along a 10-20 foot buffer from the top of the slope
- Learn to identify invasive species, and consult best practices for control
The above best practices are adapted from techniques identified in the MN DNR's Conserving your blufflands booklet that was intended for property owners along the St. Croix River.
Additional information about bluff and steep slope protections are found in the MN DNR's shoreland management best practices here: https://www.dnr.state.mn.us/waters/watermgmt_section/shoreland/bluff-slope-protections.html.
Best practices for eco-friendly yards are provided by Hennepin County's website here: https://www.hennepin.us/residents/environment/protecting-land-water#landowner-guide.
Grants are available to private property owners for small and large projects that implement some of the best practices listed above.
Hennepin County offers Natural Resource Grants for a variety of projects that preserve and restore natural areas. More information is found here: https://www.hennepin.us/residents/environment/natural-resources-funding
The Lower Minnesota River Watershed District offers a Cost-Share Grant for properties within its district (see map above). More information is found here: http://lowermnriverwd.org/resources/grants-cost-sharing
For properties in the Nine Mile Creek Watershed District, there is also a Cost-Share Grant available to landowners. More Information is found here: https://www.ninemilecreek.org/get-involved/grants/
The Riley Purgatory Bluff Creek Watershed District also offers grants to landowners within its district for small and large projects. Learn more here: http://www.rpbcwd.org/grants