Best Management Practices
Stormwater management can often be accomplished with Best Management Practices, or BMPs. BMPs are a way to alleviate the negative effects of increased stormwater runoff. BMPs, by definition, "when used singly or in combination, prevent or reduce the release of pollutants to waters of the state." -Minnesota Stormwater Manual.
BMPs are a form of Low Impact Development, or LID.
Low Impact Development
Low Impact Development (LID) is an approach to land development (or re-development) that works with nature to manage stormwater as close to its source as possible. LID tries to preserve and recreate natural landscape features to decrease imperviousness on site and create functional and appealing site drainage that treats stormwater as a resource rather than a waste product.
For an Overview of MPCA's Minimum Impact Design Standards for Low Impact Development, click here.
Photos and content courtesy of MPCA
Basic principles of Low Impact Development
- Stormwater is a resource
- Reduce impervious surfaces to allow water to soak into the ground where it lands
- Use natural systems to promote infiltration of water
- Protect ecologically important areas of proposed developments
Why Low Impact Development is important
- Many LID practices prove to be attractive amenities to a neighborhood, using them may increase property values
- Using LID practices and structures may reduce the overall cost of stormwater management
- LID practices encourage rain to soak into the ground where it falls. This results in fewer opportunities for water to collect pollutants and reach nearby waters
- MPCA and stakeholders are exploring how LID practices may help cities and townships achieve certain stormwater regulatory requirements under the Clean Water Act
There are many practices that have been used to achieve these principles like bioretention facilities, rain gardens, vegetated rooftops, rain barrels and native perennial vegetation . By implementing Low Impact Development, water can be managed in a way that reduces the impact of built areas and promotes the natural movement of water within an ecosystem or watershed. Applied on a broad scale, Low Impact Development can maintain or restore a watershed's hydrologic and ecological functions.
- Vegetated filter strips at the edges of paved surfaces or buffer strips along waterways
- Residential or commercial rain gardens designed to capture and soak in stormwater
- Porous pavers, porous concrete, and porous asphalt
- Narrower streets
- Rain barrels and cisterns
- Green roofs
Examples of Best Management Practices throughout PRWD
There are hundreds of low impact development/green infrastructure practices installed in Minnesota. Here are some sites with case studies.