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*[https://stormwater.pca.state.mn.us/index.php?title=Water_quality_benefits_of_Green_Stormwater_Infrastructure Water quality]: Bioretention is an excellent stormwater treatment practice due to the variety of pollutant removal mechanisms, including vegetative filtering, settling, evaporation, infiltration, transpiration, biological and microbiological uptake, and soil adsorption. Bioretention can be designed as an effective [https://stormwater.pca.state.mn.us/index.php?title=Stormwater_infiltration_Best_Management_Practices infiltration] / recharge practice, particularly when parent soils have high permeability (> ~ 0.5 inches per hour). Bioretention designed for infiltration (bioinfiltration) removes 100 percent of pollutants for the portion of runoff water that is infiltrated, although there [https://stormwater.pca.state.mn.us/index.php?title=Surface_water_and_groundwater_quality_impacts_from_stormwater_infiltration may be impacts to shallow groundwater]. Bioretention designed as filtration (biofiltration) employs engineered media that is effective at removing solids, most metals, and most organic chemicals. Removal of phosphorus depends on the media ([https://stormwater.pca.state.mn.us/index.php?title=Design_criteria_for_bioretention#Addressing_phosphorus_leaching_concerns_with_media_mixes link here]). Links to water quality information for bioretention - [https://stormwater.pca.state.mn.us/index.php?title=Pollutant_removal_percentages_for_bioretention_BMPs]; [https://stormwater.pca.state.mn.us/index.php?title=Pollutant_concentrations_for_bioretention_BMPs]
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*[https://stormwater.pca.state.mn.us/index.php?title=Water_quality_benefits_of_Green_Stormwater_Infrastructure Water quality]:  
*[https://stormwater.pca.state.mn.us/index.php?title=Water_quantity_and_hydrology_benefits_of_Green_Stormwater_Infrastructure Water quantity and hydrology]: Bioretention can be designed as an effective infiltration / recharge practice when parent soils have high permeability. For lower permeability soils an [https://stormwater.pca.state.mn.us/index.php?title=Glossary#U underdrain] is typically used and some infiltration and rate control can be achieved.
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*[https://stormwater.pca.state.mn.us/index.php?title=Water_quantity_and_hydrology_benefits_of_Green_Stormwater_Infrastructure Water quantity and hydrology]:  
*Climate resiliency: It is unclear if bioretention provides benefits for climate resiliency. Carbon may be sequestered, particularly if shrubs and trees exist in the practice. Bioretention also provides some reduction in peak flow. Carbon emissions for construction and maintenance may offset carbon benefits ([https://www.researchgate.net/publication/276100905_Predicting_the_carbon_footprint_of_urban_stormwater_infrastructure Moore and Hunt], 2013). [http://www.ohiowea.org/docs/OWEA_BRC+PP_Winston.pdf Winston (2016)] provides a detailed analysis of resiliency of bioretention systems based on different design considerations, such as bowl depth and vegetation utilized in the practice. A complex of wetland types interspersed with upland nesting cover provides optimum habitat but is difficult to achieve in most urban environments ([https://www.dnr.state.mn.us/excavatedponds/index.html];).
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*Climate resiliency:  
 
*Habitat improvement: Constructed wetlands, designed to retain a permanent pool, provide excellent wildlife habitat. Many wildlife species are dependent on or otherwise utilize wetland habitats, including waterfowl, wading birds, shorebirds and songbirds, furbearers such as beaver, muskrat and mink, and a variety of reptiles and amphibians like turtles, snakes, frogs, salamanders, and toads. An important factor affecting the habitat value of a constructed wetland is the surrounding landscape.  
 
*Habitat improvement: Constructed wetlands, designed to retain a permanent pool, provide excellent wildlife habitat. Many wildlife species are dependent on or otherwise utilize wetland habitats, including waterfowl, wading birds, shorebirds and songbirds, furbearers such as beaver, muskrat and mink, and a variety of reptiles and amphibians like turtles, snakes, frogs, salamanders, and toads. An important factor affecting the habitat value of a constructed wetland is the surrounding landscape.  
*Community livability: Bioretention is an aesthetically pleasing practice that can easily be incorporated into various landscapes. A variety of vegetation can also be used, including perennial plants, shrubs, and trees.
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*Community livability: Constructed ponds are an aesthetically pleasing practice. However, they require space and are difficult to incorporate in urban landscapes. A variety of vegetation can also be used, including perennial plants, shrubs, and trees.
 
*Health benefits: Green spaces may also improve mental and physical health for residents and reduce crime ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5663018/ Barton and Rogerson], 2017).
 
*Health benefits: Green spaces may also improve mental and physical health for residents and reduce crime ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5663018/ Barton and Rogerson], 2017).
*Economic savings: Properly designed and integrated bioretention practices provide life cycle cost savings. Well designed and maintained bioretention practices increase property values.
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*Economic savings: Properly designed and integrated constructed wetland practices provide life cycle cost savings. Well designed and maintained constructed wetland practices increase property values.

Revision as of 19:48, 30 May 2018

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This page is in development

Stormwater wetlands are similar in design to stormwater ponds and mainly differ by their variety of water depths and associated vegetative complex. They require slightly more surface area than stormwater ponds for the same contributing drainage area. Stormwater wetlands are constructed stormwater management practices, not natural wetlands. Like ponds, they can contain a permanent pool and temporary storage for water quality control and runoff quantity control.

Green Infrastructure benefits of constructed wetlands

Benefit Effectiveness Notes
Water quality
Primary benefit is retention of sediment; may export phosphorus if not designed and maintained properly.
Water quantity/supply
Rate control benefit.
Energy savings
Climate resiliency
Provides some rate control. Impacts on carbon sequestration are uncertain.
Air quality
Habitat improvement
Use of perennial vegetation and certain media mixes promote invertebrate communities.
Community livability
Aesthetically pleasing and can be incorporated into a wide range of land use settings.
Health benefits
Economic savings
Generally provide cost savings vs. conventional practices over the life of the practice.
Macroscale benefits
Individual practices are typically microscale, but multiple practices, when incorporated into a landscape design, provide macroscale benefits such as wildlife corridors.
Level of benefit: ◯ - none; - small; - moderate; - large; - very high
  • Water quality:
  • Water quantity and hydrology:
  • Climate resiliency:
  • Habitat improvement: Constructed wetlands, designed to retain a permanent pool, provide excellent wildlife habitat. Many wildlife species are dependent on or otherwise utilize wetland habitats, including waterfowl, wading birds, shorebirds and songbirds, furbearers such as beaver, muskrat and mink, and a variety of reptiles and amphibians like turtles, snakes, frogs, salamanders, and toads. An important factor affecting the habitat value of a constructed wetland is the surrounding landscape.
  • Community livability: Constructed ponds are an aesthetically pleasing practice. However, they require space and are difficult to incorporate in urban landscapes. A variety of vegetation can also be used, including perennial plants, shrubs, and trees.
  • Health benefits: Green spaces may also improve mental and physical health for residents and reduce crime (Barton and Rogerson, 2017).
  • Economic savings: Properly designed and integrated constructed wetland practices provide life cycle cost savings. Well designed and maintained constructed wetland practices increase property values.