Actions local governments can take to slow algae growth

Aerial view of mixed conifer-hardwood forest in northeastern Minnesota

State shoreland rules are insufficient to protect shoreland resources against climate trends

The 1989 shoreland rules were designed to manage smaller scale development common in the 1980s. The rules did not anticipate the amount of phosphorus generated by contemporary development or how intense rain would increase phosphorus flows into surface waters and how warming waters would accelerate the growth of algae. Many local governments recognize these limitations and have taken steps to protect their lake and river resources, shoreland tax base, and recreation-based businesses from the impacts of contemporary development and climate trends.

 

1. Protect and restore shoreline vegetation

Shoreline vegetation is the most cost-effective approach to reduce the flow of phosphorus into surface waters. It slows, captures, and infiltrates phosphorus-laden runoff before it gets into surface waters. It also stabilizes soils and banks against the onslaught of driving rains reducing erosion of phosphorus-laden soil into surface waters. Shoreline vegetation provides critical habitat for birds, amphibians, and mammals important to healthy lakes and rivers. Shoreline vegetation also enhances lakeshore character and natural beauty and are a natural deterrent to nuisance geese, who avoid places where predators could hide. Examples of local actions include:

  • Requiring natural vegetative buffers meeting specific standards (size, species, mix, etc.)
  • Restricting the use of retaining walls and riprap to only those areas where erosion cannot be addressed through vegetation.
  • Requiring all riprap installations to include a vegetative buffer meeting specific standards.
  • Set quantifiable limits for vegetation removal to accommodate for view corridors and shoreline recreational facilities
  • Requiring a vegetation removal permit and adopt restoration standards for violations.

Many local governments are already taking these actions. For specific examples , see innovative vegetation management, retaining walls, and riprap standards.

 

2. Limit lawns and hard surfaces, especially in the Shore Impact Zone.

The closer lawns and hard surfaces are to the water, the more quickly phosphorus-laden runoff can reach it. Lawns and hard surfaces, including permeable pavement - reduce the benefits provided by natural vegetation. Examples of local actions include:

  • Prohibiting or limiting hard surfaces and lawns in the shore impact zone.
  • Specifying limits on hard surfaces and lawns within the structure setback.
  • Reducing the hard surface limits allowed per lot, especially for new development and development on waterbodies most sensitive to climate change.
  • Only approving variances from impervious coverage standards with specific mitigating conditions such as restoring or expanding riparian buffers, naturally vegetated swales, and rain gardens.

Many local governments are already taking these actions. For specific examples, see innovative impervious surface standards.

 

3. Keep structures and septic systems away from the water and bluffs.

Structures also take the place and reduce the benefits of natural vegetation. Constructing structures requires significant land alteration and vegetation removal, producing phosphorus runoff to surface waters before, during, and after construction. Examples of local actions include:

  • Increasing structure and septic system setbacks from waters.
  • Only allowing limited expansion of nonconforming structures when shoreland buffers are restored or expanded.
  • Increasing structure setbacks from bluffs.
  • Requiring septic system setbacks from bluffs.

Many local governments are already taking these actions. For specific examples see  innovative structure setback, septic, and bluff standards.

 

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