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Minnesota Stormwater Manual

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Welcome to the '''Minnesota Stormwater Manual''' website. The Manual is designed to be a user-friendly and flexible document that guides users directly to the information they need, depending upon the question they need to answer or Best Management Practice (BMP) they need to design. This website was developed in an interactive wiki format to make it easy for the user to get to the subject of interest and to move between subjects. You can access the [[Stormwater Manual Table of Contents|Manual Table of Contents]] by clicking on the link below.
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{{alert|We have begun adding hover box (mouse over) text so users can see the contents on a particular page. Hover your mouse over the bolded text '''See contents''' next to each link below to see the contents on the linked page.|alert-info}}
  
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{{alert|Taking advantage of the wiki technology, we continue to update this manual as resources allow. We continue to value your input. If you have comments or suggestions on the format please send them to us using the ''Help Improve this Page'' box at the bottom of most pages or send an email to [mailto:paula.kalinosky@state.mn.us Paula Kalinosky at the MPCA.]|alert-info}}
  
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<strong><font size="5"><center>[[Stormwater Manual Table of Contents]]</center></font></strong>
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[[file:Check it out.png|200px|thumb|alt=check it out image|<font size=3>
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*[https://stormwater.pca.state.mn.us/index.php?title=Minnesota_Stormwater_Manual_emails Join our email list]<br>
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*[https://stormwater.pca.state.mn.us/index.php?title=Minnesota_Stormwater_Manual_email_Updates See past email postings]<br>
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*[https://app.sharebase.com/#/folder/40078/share/185-BJp5uVhHk8F694jNfUe0Nu--Q-Ck Download MIDS calculator]
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</font size>]]
  
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Welcome to the '''Minnesota Stormwater Manual''' website. This website was developed using [https://www.mediawiki.org/wiki/MediaWiki Mediawiki], a wiki application that allows for easy editing and that has powerful search abilities. See [[Introduction to the wiki]] for more information.
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==Introduction to the Minnesota Stormwater Manual==
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*[[About the Minnesota Stormwater Manual]]
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*[[Finding a topic|Help]]
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*[http://stormwater.pca.state.mn.us/index.php/About_the_Minnesota_Stormwater_Manual#Disclaimers Disclaimers]
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==Stormwater concepts and stormwater management==
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*[[General stormwater information]]
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<!--*[[Stormwater hydrology]]-->
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*[[Stormwater treatment concepts]] - <span title="1.Integrated stormwater management, 2.Treatment trains, 3.Using the treatment train approach to BMP selection, 4.Stormwater treatment train for a parking lot, 5.Stormwater treatment train for an ultra-urban setting, 6.Stormwater treatment train for a site with limited infiltration capacity, 7.Stormwater treatment train for a retrofit site, 8.Stormwater treatment train for constructed ponds in new development, 9.Case studies for stormwater treatment trains, 10.Process for selecting Best Management Practices"> '''See contents'''</span>
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*[http://stormwater.pca.state.mn.us/index.php/Alleviating_compaction_from_construction_activities Alleviating compaction from construction activities]
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*[[Liners for stormwater management]]
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*[[Green Stormwater Infrastructure (GSI) and sustainable stormwater management]]
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<!--*[[Green Infrastructure for stormwater management]] - NOTE, this page will eventually be replaced by [[Green Stormwater Infrastructure (GSI) and sustainable stormwater management]]-->
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*[[Information on soil]] - <span title="1.Soil classification, 2.Soil texture and structure, 3.Soil erodibility, 4.Soil infiltration, 5.Soil properties, 6.Soil water storage properties, 7.Specific yields for geologic materials, 8.Design infiltration rates, 9.Determining soil infiltration rates, 10.Understanding and interpreting soils and soil boring reports, 11.Soil management, 12.Alleviating compaction from construction activities, 13.Erosion prevention practices, 14.Sediment control practices"> '''See contents'''</span>
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*[[Compost and stormwater management]]
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[[file:Check it out.png|200px|thumb|alt=image|<font size=3>The [https://www.itrcweb.org/ Interstate Technology and Regulatory Council] (ITRC) released a new guidance document called [https://stormwater-1.itrcweb.org/ Stormwater Best Management Practices Performance Evaluation].</font size>]]
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==Stormwater issues==
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*[[Stormwater pollutants]] - <span title="1.Total suspended solids, 2.Phosphorus, 3.Bacteria"> '''See contents'''</span>
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*[[Stormwater infiltration]] - <span title="1.Overview, 2.Pretreatment considerations, 3.Infiltration BMPs, 4.Pollutant fate and transport in infiltration systems, 5.Surface water and groundwater quality impacts from infiltration, 6.Groundwater mounding, 7.Separation distances, 8.Permit requirements, 9.Infiltration constraints: a.Karst, b.Shallow soils and shallow depth to bedrock, c.Shallow groundwater, d.Soils with low infiltration capacity, e.Potential stormwater hotspots, f.Wellhead protection, g.Contaminated soils and groundwater, 10.Amending soils with rapid or high infiltration rates, 11.Determining soil infiltration, 12.Determining soil infiltration rates, 13.Design infiltration rates, 14.Understanding and interpreting soils and soil boring reports for infiltration BMPs, 15.References and supporting material"> '''See contents'''<span>
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*[[Protection and restoration of receiving waters]]
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*[[Minnesota specific issues]] - <span title="1. Cold climate impact on runoff management, 2.Mosquito control and stormwater management, 3.Managing stormwater sediments, 4.Minnesota plant lists, 5.Special waters and other sensitive receiving waters, 6.Road salt, smart salting, and winter maintenance, 7.Stormwater management for lake protection and restoration, 8.Minnesota maps, 9.Pollinator friendly Best Management Practices, 10.Pollinator specific plants"> '''See contents'''</span>
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*[[Stormwater and landscape guidance for solar farms and solar projects ]]
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*[[Guidance for managing sediment and wastes collected by pretreatment practices]]
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*[[Management of soil and engineered media removed from bioretention basins and similar stormwater treatment devices]]
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==Stormwater control practices (Best Management Practices)==
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<imagemap>
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Image:Stormwater BMPs.png|500px|thumb|alt=imagemap for stormwater BMPs|Stormwater Best Management Practices. Mouse hover over an '''i''' box to read a description of the practice, or click on an '''i''' box to go to a page on the practice.
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circle 30 125 30 [[Infiltration|Infiltration basins, infiltration trenches, dry wells, and underground infiltration systems capture and temporarily store stormwater before allowing it to infiltrate into the soil. As the stormwater penetrates the underlying soil, chemical, biological and physical processes remove pollutants and delay peak stormwater flows.]]
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circle 270 125 30 [[Bioretention|Bioretention (rain garden) is a terrestrial-based (up-land as opposed to wetland) water quality and water quantity control process. Bioretention employs a simplistic, site-integrated design that provides opportunity for runoff infiltration, filtration, storage, and water uptake by vegetation.]]
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circle 600 125 30 [[Trees|Tree trenches and tree boxes (collectively called tree BMP(s)), the most commonly implemented tree BMPs, can be incorporated anywhere in the stormwater treatment train but are most often located in upland areas of the treatment train. The strategic distribution of tree BMPs help control runoff close to the source where it is generated. Tree BMPs can mimic certain physical, chemical, and biological processes that occur in the natural environment.]]
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circle 690 150 30 [[Permeable pavement|Permeable pavements allow stormwater runoff to filter through surface voids into an underlying stone reservoir for temporary storage and/or infiltration. The most commonly used permeable pavement surfaces are pervious concrete, porous asphalt, and permeable interlocking concrete pavers (PICP). Permeable pavements have been used for areas with light traffic at commercial and residential sites to replace traditional impervious surfaces in low-speed roads, alleys, parking lots, driveways, sidewalks, plazas, and patios.]]
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circle 920 125 30 [[Stormwater and rainwater harvest and use/reuse|A stormwater harvesting and use system is a constructed system that captures and retains stormwater for beneficial use at a different time or place than when or where the stormwater was generated. A stormwater harvesting and use system potentially has four components: collection system (which could include the catchment area and stormwater infrastructure such as curb, gutters, and stormsewers), storage unit (such as a cistern or pond) treatment system: pre and post (that removes solids, pollutants and microorganisms, including any necessary control systems), if needed, and the distribution system (such as pumps, pipes, and control systems).]]
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circle 1130 125 30 [[Green roofs|Green roofs consist of a series of layers that create an environment suitable for plant growth without damaging the underlying roof system. Green roofs create green space for public benefit, energy efficiency, and stormwater retention/ detention. Green roofs occur at the beginning of stormwater treatment trains. Green roofs provide filtering of suspended solids and pollutants associated with those solids, although total suspended solid (TSS) concentrations from traditional roofs are generally low. Green roofs provide both volume and rate control, thus decreasing the stormwater volume being delivered to downstream Best Management Practices (BMPs).]]
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circle 30 325 30 [[Dry swale (Grass swale)|Dry swales, sometimes called grass swales, are similar to bioretention cells but are configured as shallow, linear channels. They typically have vegetative cover such as turf or native perennial grasses. Dry swales may be constructed as filtration or infiltration practices, depending on soils. If soils are highly permeable (A or B soils), runoff infiltrates into underlying soils. In less permeable soils, runoff is treated by engineered soil media and flows into an underdrain, which conveys treated runoff back to the conveyance system further downstream. Check dams incorporated into the swale design allow water to pool up and infiltrate into the underlying soil or engineered media, thus increasing the volume of water treated.]]
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circle 270 325 30 [[Wet swale (wetland channel)|Wet swales occur when the water table is located very close to the surface or water does not readily drain out of the swale. A wet swale acts as a very long and linear shallow biofiltration or linear wetland treatment system. Wet swales do not provide volume reduction and have limited treatment capability. Incorporation of check dams into the design allows treatment of a portion or all of the water quality volume within a series of cells created by the check dams. Wet swales planted with emergent wetland plant species provide improved pollutant removal. Wet swales may be used as pretreatment practices. Wet swales are commonly used for drainage areas less than 5 acres in size.]]
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circle 600 325 30 [[High-gradient stormwater step-pool swale|Stormwater step pools address higher energy flows due to more dramatic slopes than dry or wet swales. Using a series of pools, riffle grade control, native vegetation and a sand seepage filter bed, flow velocities are reduced, treated, and, where applicable, infiltrated. The physical characteristics of the stormwater step pools are similar to Rosgen A or B stream classification types, where “bedform occurs as a step/pool, cascading channel which often stores large amounts of sediment in the pools associated with debris dams”. Stormwater step pools are designed with a wide variety of native plant species depending on the hydraulic conditions and expected post-flow soil moisture at any given point within the stormwater step pool.]]
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circle 820 325 30 [[Vegetated filter strips|Vegetated filter strips are designed to remove solids from stormwater runoff. The vegetation can consist of natural and established vegetation communities and can range from turf grass to woody species with native grasses and shrubs. Because of the range of suitable vegetation communities, vegetated filter strips can be easily incorporated into landscaping plans; in doing so, they can accent adjacent natural areas or provide visual buffers within developed areas. They are best suited for treating runoff from roads, parking lots and roof downspouts. Their primary function is to slow runoff velocities and allow sediment in the runoff to settle or be filtered by the vegetation. By slowing runoff velocities, they help to attenuate flow and create a longer time of concentration. Filter strips do not significantly reduce runoff volume, but there are minor losses due to infiltration and depression storage. Filter strips are most effective if they receive sheet flow and the flow remains uniformly distributed across the filter strip.]]
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circle 1040 325 30 [[Iron enhanced sand filter (Minnesota Filter)|Iron-enhanced sand filters are filtration Best Management Practices (BMPs) that incorporate filtration media mixed with iron. The iron removes several dissolved constituents, including phosphate, from stormwater. Iron-enhanced sand filters may be particularly useful for achieving low phosphorus levels needed to improve nutrient impaired waters. Iron-enhanced sand filters could potentially include a wide range of filtration BMPs with the addition of iron; however, iron is not appropriate for all filtration practices due to the potential for iron loss or plugging in low oxygen or persistently inundated filtration practices.]]
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circle 1130 325 30 [[Filtration|Sand (media) filters have widespread applicability and are suitable for all land uses, as long as the contributing drainage areas are limited (e.g., typically less than 5 acres). Sand filters are not as aesthetically appealing as bioretention, which makes them more appropriate for commercial or light industrial land uses or in locations that will not receive significant public exposure. Sand filters are particularly well suited for sites with high percentages of impervious cover (e.g., greater than 50 percent). Sand filters can be installed underground to prevent the consumption of valuable land space (often an important retrofit or redevelopment consideration).]]
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circle 170 525 30 [[Stormwater ponds|Stormwater ponds are typically installed as an end-of-pipe BMP at the downstream end of the treatment train. Stormwater pond size and outflow regulation requirements can be significantly reduced with the use of additional upstream BMPs. However, due to their size and versatility, stormwater ponds are often the only management practice employed at a site and therefore must be designed to provide adequate water quality and water quantity treatment for all regulated storms.]]
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circle 265 525 30 [[Stormwater wetlands|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. Wetlands are widely applicable stormwater treatment practices that provide both water quality treatment and water quantity control. Stormwater wetlands are best suited for drainage areas of at least 10 acres. When designed and maintained properly, stormwater wetlands can be an important aesthetic feature of a site.]]
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circle 600 525 30 [[Pretreatment|Pretreatment practices are installed immediately preceding one or more structural stormwater BMPs. Pretreatment reduces maintenance and prolongs the lifespan of structural stormwater BMPs by removing trash, debris, organic materials, coarse sediments, and associated pollutants prior to entering structural stormwater BMPs. Implementing pretreatment devices also improves aesthetics by capturing debris in focused or hidden areas.]]
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circle 820 510 30 [[Sediment control practices|Sediment control practices are designed to prevent or minimize loss of eroded soil at a site. Typical sediment control practices focus on 1) physical filtration of sediment by trapping soil particles as water passes through a silt fence, drop inlet screen, fiber roll, etc., 2)settling processes, that allow sediment to fall out of flows that are slowed and temporarily impounded in ponds, traps, or in small pools created by berms, silt fencing, inlet protection dikes, check dams, etc.]]
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circle 1040 500 30 [[Erosion prevention practices|Erosion prevention practices include 1) planning approaches that minimize the size of the bare soil area and the length of time disturbed areas are exposed to the elements – especially for long, steep slopes and easily erodible soils, 2) diverting or otherwise controlling the location and volume of run-on flows to the site from adjacent areas, 3)keeping concentrated flows in ditches stabilized with vegetation, rock, or other material, and 4)covering bare soil with vegetation, mulch, erosion control blankets, turf reinforcement mats, gravel, rock, plastic sheeting, soil binder chemicals, etc.]]
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circle 1255 525 30 [[Pollution prevention|Pollution prevention (P2) is a “front-end” method to decrease costs, risks, and environmental concerns. In contrast to managing pollution after it is created, P2 reduces or eliminates waste and pollution at its source. P2 includes a variety of residential, municipal, and industrial practices.]]
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</imagemap>
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By type
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*[https://stormwater.pca.state.mn.us/index.php?title=Construction_stormwater_program#Best_Management_Practices Construction stormwater Best Management Practices] - <span title="1.Erosion prevention practices, 2.Sediment control practices, 3.Construction stormwater treatment, 4.Construction practices to minimize sediment discharge, 5.Winter construction practices for site stabilization, erosion prevention and sediment control, 6.General principles for erosion prevention and sediment control at construction sites in Minnesota, 7.Construction stormwater inspection checklist">'''See Contents'''</span>
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*[[Pretreatment|Pretreatment practices]] - <span title="1.Pretreatment selection tool, 2.Overview, methods and types of pretreatment, 3.Settling devices, 4.Screens, 5.Vegetated filter strips, 6.Hydrodynamic separation devices, 7.Screening and straining devices, including forebays, 8.Above ground and below grade storage and settling devices, 9.Filtration devices and practices, 10.Pretreatment sizing, 11.Managing sediment and wastes collected by pretreatment practices, 12.Tabled information for pretreatment practices">'''See contents'''</span>
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*[[Post-construction stormwater Best Management Practices|Post-construction practices]] - <span title="1.Pretreatment, 2.Infiltration practices, 3.Filtration practices, 4.Sedimentation practices">'''See Contents'''</span>
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*[[Structural stormwater Best Management Practices|Structural practices]] - <span title="1.Green roofs, 2.Permeable pavement, 3.Trees, 4.Bioretention, 5.Infiltration trench, basin, dry well, and underground infiltration, 6.Dry swale (Grass swale), 7.Wet swale (wetland channel), 8.High-gradient stormwater step-pool swale, 9.Sand filters, 10.Iron enhanced sand filter, 11.Stormwater ponds, 12.Stormwater wetlands, 13.Vegetated filter strips, 14.Hydrodynamic separation devices, 15.Pretreatment screening and straining devices, including forebays, 16.Above and below grade pretreatment storage and settling devices, 17.Pretreatment filtration devices, 18.Chemical treatment">'''See Contents'''</span>
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*[[Stormwater and rainwater harvest and use/reuse]]
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*[[Non-structural stormwater Best Management Practices|Non-structural practices]] - <span title="1.Road de-icing, 2.Pollution prevention, 3.Better site design, 4.Stormwater re-use and rainwater harvesting, 5.Street sweeping">'''See contents'''</span>
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**[[Street sweeping]]
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By treatment mechanism
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*[[Pretreatment|Pretreatment practices]] - <span title="1.Pretreatment selection tool, 2.Overview, methods and types of pretreatment, 3.Settling devices, 4.Screens, 5.Vegetated filter strips, 6.Hydrodynamic separation devices, 7.Screening and straining devices, including forebays, 8.Above ground and below grade storage and settling devices, 9.Filtration devices and practices, 10.Pretreatment sizing, 11.Managing sediment and wastes collected by pretreatment practices, 12.Tabled information for pretreatment practices">'''See contents'''</span>
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*[[Stormwater filtration Best Management Practices|Filtration practices]] - <span title="Permeable pavement, 2.Trees, 3.Bioretention - biofiltration, 4.Dry swale (Grass swale) with underdrain, 5.Wet swale (wetland channel), 6.High-gradient stormwater step-pool swale with underdrain, 7.Sand filter, 8.Iron enhanced sand filter, 9.Green roofs, 10.Turf, 11.Vegetated filter strips, 12.Manufactured devices, 13.Filtration devices">'''See contents'''</span>
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*[[Stormwater infiltration Best Management Practices|Infiltration practices]] - <span title="1.Permeable pavement, 2.Tree trench/tree box, 3.Bioretention - bioinfiltration (Rain Gardens), 4.Infiltration trench, including dry wells, 5.Infiltration basin, 6.Underground infiltration, 7.Dry swale (Grass swale), 8.High-gradient stormwater step-pool swale, 9.Stormwater and rainwater harvest and use/reuse, 10.Turf, 11.Understanding and interpreting soils and soil boring reports, 12. Determining soil infiltration rates"> '''See contents'''</span>
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*[[Stormwater sedimentation Best Management Practices|Sedimentation practices]] - <span title="1.Stormwater ponds, 2.Stormwater wetlands, 3.Hydrodynamic devices">'''See contents'''</span>
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*[[Stormwater chemical Best Management Practices|Chemical practices]] - <span title="1.Iron enhanced sand filter, 2.Chemical treatment, 3.Soil amendments to enhance phosphorus sorption.">'''See Contents'''</span>
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==Regulatory, permitting==
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*[[Construction stormwater program|Construction stormwater: Permit, documents, fact sheets]]
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*[[Stormwater Program for Municipal Separate Storm Sewer Systems (MS4)|Municipal stormwater: Permit, documents, fact sheets]]
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*[[Industrial stormwater program|Industrial stormwater: Permit, documents, fact sheets]]
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*[[Regulatory information]]
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*[[Additional regulatory information]]
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==Models, calculations, methodologies, pollutant removal, credits==
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*[[Minimal Impact Design Standards]]
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*[[Minnesota Pollution Control (MPCA) Simple Estimator]]
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*[[Stormwater models, calculators and modeling]]
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*[[Stormwater pollutant removal, stormwater credits]]
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*[http://stormwater.pca.state.mn.us/index.php/Unified_sizing_criteria_section Unified sizing criteria]
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==Case studies and examples==
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*[https://stormwater.pca.state.mn.us/index.php?title=Category:Level_2_-_Case_studies_and_examples/Case_studies Case studies]
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*[https://stormwater.pca.state.mn.us/index.php?title=Category:Level_2_-_Best_management_practices/Case_studies_and_examples Best management practice case studies]
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*[https://stormwater.pca.state.mn.us/index.php?title=Category:Level_2_-_Case_studies_and_examples/Examples Examples]
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==Communications and outreach==
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[[File:Webinar training image.jpg|thumb|250px|alt=image|[https://stormwater.pca.state.mn.us/index.php?title=Training_and_webinar_schedule Training and webinar schedule]. Image: Microsoft stock image]]
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*[[Stormwater newsletters]]
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*[[Stormwater blogs]]
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*[[In the news]]
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*[[Stormwater Manual webinars]]
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*[[MIDS calculator videos]]
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*[https://stormwater.pca.state.mn.us/index.php?title=Training_and_workshop_materials_and_modules MIDS training and workshop materials]
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*[[Stormwater videos]]
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*[[Training and webinar schedule]]
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*[[Descriptions of training and webinar events]]
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*[[Minnesota Stormwater Manual email Updates]]
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==Stormwater research and education==
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*[[Stormwater education]]
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*[[Stormwater research]]
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*[http://stormwater.safl.umn.edu/ University of Minnesota St. Anthony Falls Stormwater Research]
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==Reference==
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*[[Minnesota Stormwater Manual photo galleries]]
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*[https://stormwater.pca.state.mn.us/index.php?title=Category:Level_2_-_General_information,_reference,_tables,_images,_and_archives/Tables Tables]
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*[[Minnesota plant lists|Plant information]]
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*[[Images, CAD drawings]]: Includes links to CAD drawings, photos, schematics, graphs, and other images
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*[http://stormwater.pca.state.mn.us/index.php?title=Category:Checklist&action=edit&redlink=1 Checklists]
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*[http://stormwater.pca.state.mn.us/index.php/Links_to_other_manuals Links to other stormwater manuals]
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*[[Miscellaneous information]]: Contains references, forms, links, issue papers
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*[[Acronyms]]
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*[[Symbols]]
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*[[Glossary|Glossary (definitions)]]
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*[[BMP terminology]]
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*[[Conversion units]]
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*[[References|References from the original manual]]. NOTE: Newer reference lists are associated with topics on individual pages in the manual.
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*[[Protecting Water Quality in Urban Areas: Best Management Practices for Dealing with Storm Water Runoff from Urban, Suburban, and Developing Areas of Minnesota]]
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*[[Watershed projects and virtual tours]]
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==Documents==
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*[[pdf versions of Manual topics]]
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*[[Technical support]]: Contains a variety of technical information used in developing the Manual
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[[Category:Level 2 - General information, reference, tables, images, and archives/Reference]]
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<!--[[File:Announcement.png|150px|thumb|alt=image for an announcement|<font size=3>IT'S HERE! The Minimal Impact Design Standards calculator is now available. Click [[MIDS calculator|here]]</font size>]]
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[[Image:CWL_Ammendment_logo.png|left|100px|alt=CWL Logo]]
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[[File:Question mark.png|thumb|50px|alt=image of question mark used to link users to our help page|<font size=3>Looking for something? Visit our [[Finding a topic|help]] section on finding a topic.</font size>]]-->
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<!--[[File:Question.jpg|100px|thumb|alt=clip art question mark|<font size=3>[[Quick guide|I knew where it was in the old Manual but where is it now?]]</font size>]]
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[[File:logo.jpg|thumb|right|100px|alt=stormwater manual logo|<font size=3>Access the old [http://www.pca.state.mn.us/index.php/view-document.html?gid=8937 Manual]. Note: this version is not being updated.</font size>]]-->
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<!--Welcome to the '''Minnesota Stormwater Manual''' website. The Manual is designed to be user-friendly and flexible to guide users directly to the information they need, depending upon the question they need to answer or Best Management Practice (BMP) they need to design. This website was developed in an interactive wiki format to make it easy for the user to get to the subject of interest and to move between subjects.
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<font size = 3>'''You can access the [[Stormwater Manual Table of Contents|Manual Table of Contents]] by clicking on the link below'''.</font size>
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==Submitting technical content for the website==
 
{{alert|'''Submitting technical content''': Technical content is often being developed for certain pages within this website. You may wish to submit technical content, such as documents or links, for inclusion in the Manual. You can submit technical content for consideration on those topics listed below by clicking on the appropriate link. Technical content is reviewed by a technical team that then makes recommendations for including content to the Stormwater Steering Committee Manual subgroup before final inclusion in the Manual.|alert-info}}
 
{{alert|'''Submitting technical content''': Technical content is often being developed for certain pages within this website. You may wish to submit technical content, such as documents or links, for inclusion in the Manual. You can submit technical content for consideration on those topics listed below by clicking on the appropriate link. Technical content is reviewed by a technical team that then makes recommendations for including content to the Stormwater Steering Committee Manual subgroup before final inclusion in the Manual.|alert-info}}
 
*[https://sites.google.com/site/midspermeablepavementstechteam/ Permeable pavement]-->
 
*[https://sites.google.com/site/midspermeablepavementstechteam/ Permeable pavement]-->
  
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==Acknowledgements==
 
==Acknowledgements==
 
This Manual was initiated by the Minnesota Stormwater Design Team, which evolved into the Minnesota Stormwater Steering Committee (SSC). Manual production was directed by the SSC’s Manual Sub-Committee (MSC). A listing of contributors and participants in the process appears in the [[Acknowledgements]] section.
 
This Manual was initiated by the Minnesota Stormwater Design Team, which evolved into the Minnesota Stormwater Steering Committee (SSC). Manual production was directed by the SSC’s Manual Sub-Committee (MSC). A listing of contributors and participants in the process appears in the [[Acknowledgements]] section.
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==Guidance on use of the website==
 
==Guidance on use of the website==
 
For new users of this website, we have provided [[Guidance on how to use this website and the Manual]].
 
For new users of this website, we have provided [[Guidance on how to use this website and the Manual]].
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==What's new?==
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We will attempt to provide frequent [[updates]] to users of the Manual. Updates will focus primarily on content of the Manual and will not include minor changes and corrections.
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We will attempt to provide frequent updates to users of the Manual. Updates will focus primarily on content of the Manual and will not include minor changes and corrections.
  
 
==Frequently asked questions (How do I ...?)==
 
==Frequently asked questions (How do I ...?)==
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Below are some quick links to answer the question: "How do I..."
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*Determine if I am covered by the Phase II Construction, MS4 or Industrial permit rules? See [[Regulatory information]], Stormwater Program.
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*Pick proper quantity and quality modeling/hydrological factors? See [[Available stormwater models and selecting a model]], [[Recommended models and calculators for volume, water quality and credit calculations]], or [[Calculating stormwater volume and pollutant reductions and credits]]
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*Pick a BMP? See [[Using the treatment train approach to BMP selection]] or [[Process for selecting Best Management Practices]]
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*Design a BMP? Chapters for each structural BMP in this manual have aan article on design criteria. You may access an article on design criteria by going to the BMP of interest. All articles on design criteria have also been combined as a category. You can access categories in the left toolbar. In the Navigation section, click on '''''Categories''''' and follow find the link to the page called '''''Design criteria'''''.
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*Consider the effects of cold weather on the choice and operation of a BMP? > Ch. 9
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*Incorporate better site design/low impact development into my stormwater management work? > Ch. 4
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*Find out if my site impacts a “special water” ? > App. F
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*Find out what is included under the “special water” or other sensitive receiving waters categories? > Ch. 5, Ch. 10, & App. F
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*Select the proper model to use for my unique situation? > Ch. 8 & App. B
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*Know what plants to use when I’m planting a rain garden? > App. E
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*Make sure everything I need for a particular permit is accounted for? > Ch. 5 & App. G
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*Find out what a calcareous fen is and what’s required to protect it? > App. F
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*Find out how to maintain a bioretention facility or any other BMP? > Ch. 12
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*Find sample/model ordinances? > App. G
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*See what sample BMP applications have been done in the state? > Ch. 14
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*Identify the potential for ground water/surface water interactions? > Ch. 3
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*Minimize the potential for my BMP to breed mosquitoes? > Ch. 6 & Ch. 12
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*Incorporate channel protection into my pond outlet design? > Ch. 10
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*Identify which MPCA Eco-region I am operating within? > App. A
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*Explore more deeply one of the Issue Paper topics that was considered by the Manual Sub-Committee? > App. J
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*Find out which watershed (and organization) I am located within? > App. A
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*Determine the criteria I need to meet for runoff volume control? > Ch. 5 & Ch. 10
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*Quantify my water quality and flood control volume requirements? > Ch. 10
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*Maintain my rain garden? > Ch. 12
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*Deal with karst geology, tight soils, and potential stormwater hotspots of toxicity? > Ch. 13
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*Check that my BMP is suitable based on site conditions or receiving water criteria? > Ch. 7-->
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==Overview==
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Throughout the production of the Manual, one singular goal was kept in mind – to produce a useful product that helps the everyday user better manage stormwater. The purpose, goal, vision and tenets were developed by the original Stormwater Design Team. Although stormwater management to control the pollution of receiving waters has been around in earnest for over 30 years in Minnesota, the advent of many new programs means that guidance is needed more than ever. Such programs as the NPDES (National Pollutant Discharge Elimination System) Phase I and II program, the TMDL (Total Maximum Daily Load) program, and strong runoff control programs at the local and watershed levels have all contributed to the need for this information to be compiled in a comprehensive, technically sound document.
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<p>The directive the Manual Sub-Committee received from the SSC was to produce a document that could be used as a single source to guide stormwater managers through the maze of regulations, Best Management Practices (BMPs) designs, models/techniques and terminology that constitute good stormwater management. It does not address the requirements of other non-stormwater related regulatory programs that can have an effect on stormwater. Related to this was the charge to produce a Manual that does not duplicate the many good sources of information already available. Because Minnesota is fortunate enough to have had many additional tools created over the years, the Manual will often forego detailed explanation of a particular element and send the user directly to another resource via electronic linkage or cited reference. These linked resources provide information that Minnesota stormwater managers can put to use in conjunction with this Minnesota Stormwater Manual. The Manual is intended to be flexible, easily updated and responsive to the needs of the Minnesota stormwater community.</p>
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==Disclaimer==
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The Minnesota Pollution Control Agency (MPCA) (including its employees and agents) assumes no responsibility for consequences resulting from the use of information contained within this Internet website, or from use of information obtained at linked Internet addresses, or in any respect for the content of such information, including (but not limited to) errors or omissions, the accuracy or reasonableness of factual or scientific assumptions, studies or conclusions, the defamatory nature of statements, ownership of copyright or other intellectual property rights, and the violation of property, privacy, or personal rights of others. The MPCA is not responsible for, and expressly disclaims all liability for, damages of any kind arising out of use, reference to, or reliance on such information. No guarantees or warranties, including (but not limited to) any express or implied warranties of merchantability or fitness for a particular use or purpose, are made by the MPCA with respect to such information.
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At certain places on this MPCA Internet site, live "links" to other Internet addresses can be accessed. Such external Internet addresses contain information created, published, maintained, or otherwise posted by institutions or organizations independent of the MPCA. The MPCA does not endorse, approve, certify, or control these external Internet addresses and does not guarantee the availability, accuracy, completeness, efficacy, timeliness, or correct sequencing of information located at such addresses. No one should rely on the accuracy, completeness, efficacy, and timeliness of such information. Reference therein to any specific commercial product, process, or service by trade name, trademark, service mark, manufacturer, or otherwise does not constitute or imply endorsement, recommendation, or favoring by the MPCA.
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The Stormwater Steering Committee members agreed to support this Manual and relay it to the public. Although all members do not agree with all elements or concepts contained in the Manual, they did support release of the Manual as a constructive tool for use by stormwater professionals, regulators, plan reviewers, and the public. Concepts presented in this Manual are intended to be flexible guidance for users rather than stringent rules. Each stormwater problem is different, so solutions will need to be customized to address this variation. This Manual provides the tools, but the user must provide the ingenuity.</p>
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<p>This Manual provides direction and guidance for stormwater management in Minnesota. The Stormwater Steering Committee wants you, through your active use of and feedback on the [[submit Manual]], to help Minnesota reach our vision for stormwater management in Minnesota.</p>
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<p>The Manual is intended as a guidance document. It will help users identify and appropriately use the best practices to protect Minnesota’s water resources from adverse impacts associated with stormwater runoff. Some practices in the Manual go beyond today’s requirements, and are so identified. Others help to clarify how and when to use currently accepted practices to meet water quality goals. The Manual looks beyond current practices and addresses special situations such as protection of a trout stream or stormwater management in karst areas. Some practices discussed are designed to address unique site conditions and may not be readily adaptable for across-the-board applications.</p>
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<p>The Manual does not establish new regulatory requirements and does not supersede existing local, state or federal requirements. Because the Manual combines standard practices with innovative and site specific recommendations, it is strongly recommended that regulators use this Manual only as supporting guidance and not wholly incorporate the Manual by reference in regulatory requirements.</p>
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<p>Feedback from users is needed to gauge the Manual’s use and to justify ongoing updates. Case studies on the use and implementation of the Manual recommendations will be particularly useful. Please [[submit]] comments and suggested updates based on new technologies, better information, or new studies, to assist us in keeping the Manual accurate and relevant. The Stormwater Steering Committee hopes you find the Manual to be an effective tool in managing stormwater runoff in Minnesota.</p>
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==Introduction==
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“Land of 10,000 Lakes” does not capture the abundance of water and water-related resources in the state of Minnesota. Not only is Minnesota the home of more than 10,000 lakes, but there are also some 69,000 miles of rivers and streams, over nine million acres of wetlands, nearly 2,000 miles of trout streams, and ground water aquifers and surface water sources capable of producing drinking water for about four million residents.
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<p>The headwaters of the Mississippi River are located in the state and we border the largest freshwater lake in the world, Lake Superior. Protecting, restoring, and maintaining these natural resources, although challenging, must be a priority for all Minnesotans. We all contribute to the contamination that deteriorates our waterways, so it is everyone’s responsibility to minimize these threats and keep our water clean. Protecting the waters of our state plays a huge role in protecting the culture and heritage of our home.</p>
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<p>Minnesota’s water and related environment is complex which can, in turn lead to very complicated management systems. As thousands of acres of land are converted annually from rural and open areas to urbanized communities, the impacts on stormwater runoff can become extreme.</p>
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<p>With these changes to the surface of the land comes the responsibility of assuring that surrounding waters are not adversely affected. As development escalates, so does runoff. With urbanization, the natural infiltration of water into the ground is reduced. Larger runoff volumes, quicker and higher runoff peaks, and increased erosion are a few of the results that lead to more pollutants eventually making their way to the receiving waters. The challenge for all Minnesotans is to control runoff rate and volume as well as the material that this water picks up on its way to a receiving water.</p>
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<p>This Manual explores a variety of management approaches designed to lesson the impacts of development. Although other sources of runoff, such as agriculture and forestry can contribute to water quality deterioration, this Manual focuses on urban sources related to development. Totally eliminating land conversion is not a feasible option, so appropriate and innovative measures must be taken to minimize the negative impact of development. The Manual explores an array of best management practices (BMPs) that can be implemented to control sediment and reduce runoff in a practical and flexible manner on the site. The term “integrated stormwater management” encompasses all aspects of precipitation as it moves from the land surface to the receiving water.</p>
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<p>The focus of this Manual is to guide users in such a way that all possible measures are taken to ensure proper, responsible stormwater management. There are many bodies of water in Minnesota that have already been impacted by various pollutants and are in need of improvement. Any water that does not meet the water quality standards established to protect it and deem it usable for its intended purpose is classified by the Minnesota Pollution Control Agency (MPCA) as an [http://www.pca.state.mn.us/index.php/water/water-types-and-programs/minnesotas-impaired-waters-and-tmdls/minnesotas-impaired-waters-and-total-maximum-daily-loads-tmdls.html “Impaired Water.”]</p>
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<p>There are no proposals for regulatory changes in the Manual; however, there are some recommendations to improve the stormwater standards that are typically used in Minnesota. This was done with the hope of initiating discussions on methods to improve stormwater management, the definition of what constitutes an improvement, and better options for implementing such improvements. As a result of the discussions and input form Minnesota’s stormwater community, there may be the potential at some point to include some of these ideas into regulatory framework.</p>
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<p>The intent of the Manual is to promote innovation and generate ideas of new stormwater
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management practices. Users will also note that this Manual is not an erosion and sediment control handbook, nor is it a BMP manual, although there are features of each within the Manual. Again, users are directed to available resources so that this Manual did not become so long as to be cumbersome and therefore unused.</p>
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<p>Finally, the Manual primarily addresses the post-construction requirements of the NPDES MS4 permit program. Elements of the Manual exist for each of the six required Municipal Separate Storm Sewer System (MS4) components and could be used by communities to assist in preparing their permit material. Readers interested in MS4 guidelines are referred to the [http://www.pca.state.mn.us/water/stormwater/stormwater-ms4.html MPCA] web site for the MS4 program.</p>
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For information on pages undergoing revision, open [[Sites undergoing revision|this link]]
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For information on pages undergoing peer review, open [[Sites undergoing peer review|this link]]
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[[default table]]
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<!--==Submitting technical content for the website==
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{{alert|'''Submitting technical content''': Technical content is often being developed for certain pages within this website. You may wish to submit technical content, such as documents or links, for inclusion in the Manual. You can submit technical content for consideration on those topics listed below by clicking on the appropriate link. Technical content is reviewed by a technical team that then makes recommendations for including content to the Stormwater Steering Committee Manual subgroup before final inclusion in the Manual.|alert-info}}
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*[https://sites.google.com/site/midspermeablepavementstechteam/ Permeable pavement]-->
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<!--==Frequently asked questions (How do I ...?)==
 
Below are some quick links to answer the question: "How do I..."
 
Below are some quick links to answer the question: "How do I..."
 
*Determine if I am covered by the Phase II Construction, MS4 or Industrial permit rules? See [[Regulatory information]], Stormwater Program.
 
*Determine if I am covered by the Phase II Construction, MS4 or Industrial permit rules? See [[Regulatory information]], Stormwater Program.
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Latest revision as of 15:10, 2 October 2024

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Information: We have begun adding hover box (mouse over) text so users can see the contents on a particular page. Hover your mouse over the bolded text See contents next to each link below to see the contents on the linked page.
Information: Taking advantage of the wiki technology, we continue to update this manual as resources allow. We continue to value your input. If you have comments or suggestions on the format please send them to us using the Help Improve this Page box at the bottom of most pages or send an email to Paula Kalinosky at the MPCA.
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Welcome to the Minnesota Stormwater Manual website. This website was developed using Mediawiki, a wiki application that allows for easy editing and that has powerful search abilities. See Introduction to the wiki for more information.

Introduction to the Minnesota Stormwater Manual

Stormwater concepts and stormwater management

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The Interstate Technology and Regulatory Council (ITRC) released a new guidance document called Stormwater Best Management Practices Performance Evaluation.

Stormwater issues

Stormwater control practices (Best Management Practices)

Infiltration basins, infiltration trenches, dry wells, and underground infiltration systems capture and temporarily store stormwater before allowing it to infiltrate into the soil. As the stormwater penetrates the underlying soil, chemical, biological and physical processes remove pollutants and delay peak stormwater flows.Bioretention (rain garden) is a terrestrial-based (up-land as opposed to wetland) water quality and water quantity control process. Bioretention employs a simplistic, site-integrated design that provides opportunity for runoff infiltration, filtration, storage, and water uptake by vegetation.Tree trenches and tree boxes (collectively called tree BMP(s)), the most commonly implemented tree BMPs, can be incorporated anywhere in the stormwater treatment train but are most often located in upland areas of the treatment train. The strategic distribution of tree BMPs help control runoff close to the source where it is generated. Tree BMPs can mimic certain physical, chemical, and biological processes that occur in the natural environment.Permeable pavements allow stormwater runoff to filter through surface voids into an underlying stone reservoir for temporary storage and/or infiltration. The most commonly used permeable pavement surfaces are pervious concrete, porous asphalt, and permeable interlocking concrete pavers (PICP). Permeable pavements have been used for areas with light traffic at commercial and residential sites to replace traditional impervious surfaces in low-speed roads, alleys, parking lots, driveways, sidewalks, plazas, and patios.A stormwater harvesting and use system is a constructed system that captures and retains stormwater for beneficial use at a different time or place than when or where the stormwater was generated. A stormwater harvesting and use system potentially has four components: collection system (which could include the catchment area and stormwater infrastructure such as curb, gutters, and stormsewers), storage unit (such as a cistern or pond) treatment system: pre and post (that removes solids, pollutants and microorganisms, including any necessary control systems), if needed, and the distribution system (such as pumps, pipes, and control systems).Green roofs consist of a series of layers that create an environment suitable for plant growth without damaging the underlying roof system. Green roofs create green space for public benefit, energy efficiency, and stormwater retention/ detention. Green roofs occur at the beginning of stormwater treatment trains. Green roofs provide filtering of suspended solids and pollutants associated with those solids, although total suspended solid (TSS) concentrations from traditional roofs are generally low. Green roofs provide both volume and rate control, thus decreasing the stormwater volume being delivered to downstream Best Management Practices (BMPs).Dry swales, sometimes called grass swales, are similar to bioretention cells but are configured as shallow, linear channels. They typically have vegetative cover such as turf or native perennial grasses. Dry swales may be constructed as filtration or infiltration practices, depending on soils. If soils are highly permeable (A or B soils), runoff infiltrates into underlying soils. In less permeable soils, runoff is treated by engineered soil media and flows into an underdrain, which conveys treated runoff back to the conveyance system further downstream. Check dams incorporated into the swale design allow water to pool up and infiltrate into the underlying soil or engineered media, thus increasing the volume of water treated.Wet swales occur when the water table is located very close to the surface or water does not readily drain out of the swale. A wet swale acts as a very long and linear shallow biofiltration or linear wetland treatment system. Wet swales do not provide volume reduction and have limited treatment capability. Incorporation of check dams into the design allows treatment of a portion or all of the water quality volume within a series of cells created by the check dams. Wet swales planted with emergent wetland plant species provide improved pollutant removal. Wet swales may be used as pretreatment practices. Wet swales are commonly used for drainage areas less than 5 acres in size.Stormwater step pools address higher energy flows due to more dramatic slopes than dry or wet swales. Using a series of pools, riffle grade control, native vegetation and a sand seepage filter bed, flow velocities are reduced, treated, and, where applicable, infiltrated. The physical characteristics of the stormwater step pools are similar to Rosgen A or B stream classification types, where “bedform occurs as a step/pool, cascading channel which often stores large amounts of sediment in the pools associated with debris dams”. Stormwater step pools are designed with a wide variety of native plant species depending on the hydraulic conditions and expected post-flow soil moisture at any given point within the stormwater step pool.Vegetated filter strips are designed to remove solids from stormwater runoff. The vegetation can consist of natural and established vegetation communities and can range from turf grass to woody species with native grasses and shrubs. Because of the range of suitable vegetation communities, vegetated filter strips can be easily incorporated into landscaping plans; in doing so, they can accent adjacent natural areas or provide visual buffers within developed areas. They are best suited for treating runoff from roads, parking lots and roof downspouts. Their primary function is to slow runoff velocities and allow sediment in the runoff to settle or be filtered by the vegetation. By slowing runoff velocities, they help to attenuate flow and create a longer time of concentration. Filter strips do not significantly reduce runoff volume, but there are minor losses due to infiltration and depression storage. Filter strips are most effective if they receive sheet flow and the flow remains uniformly distributed across the filter strip.Iron-enhanced sand filters are filtration Best Management Practices (BMPs) that incorporate filtration media mixed with iron. The iron removes several dissolved constituents, including phosphate, from stormwater. Iron-enhanced sand filters may be particularly useful for achieving low phosphorus levels needed to improve nutrient impaired waters. Iron-enhanced sand filters could potentially include a wide range of filtration BMPs with the addition of iron; however, iron is not appropriate for all filtration practices due to the potential for iron loss or plugging in low oxygen or persistently inundated filtration practices.Sand (media) filters have widespread applicability and are suitable for all land uses, as long as the contributing drainage areas are limited (e.g., typically less than 5 acres). Sand filters are not as aesthetically appealing as bioretention, which makes them more appropriate for commercial or light industrial land uses or in locations that will not receive significant public exposure. Sand filters are particularly well suited for sites with high percentages of impervious cover (e.g., greater than 50 percent). Sand filters can be installed underground to prevent the consumption of valuable land space (often an important retrofit or redevelopment consideration).Stormwater ponds are typically installed as an end-of-pipe BMP at the downstream end of the treatment train. Stormwater pond size and outflow regulation requirements can be significantly reduced with the use of additional upstream BMPs. However, due to their size and versatility, stormwater ponds are often the only management practice employed at a site and therefore must be designed to provide adequate water quality and water quantity treatment for all regulated storms.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. Wetlands are widely applicable stormwater treatment practices that provide both water quality treatment and water quantity control. Stormwater wetlands are best suited for drainage areas of at least 10 acres. When designed and maintained properly, stormwater wetlands can be an important aesthetic feature of a site.Pretreatment practices are installed immediately preceding one or more structural stormwater BMPs. Pretreatment reduces maintenance and prolongs the lifespan of structural stormwater BMPs by removing trash, debris, organic materials, coarse sediments, and associated pollutants prior to entering structural stormwater BMPs. Implementing pretreatment devices also improves aesthetics by capturing debris in focused or hidden areas.Sediment control practices are designed to prevent or minimize loss of eroded soil at a site. Typical sediment control practices focus on 1) physical filtration of sediment by trapping soil particles as water passes through a silt fence, drop inlet screen, fiber roll, etc., 2)settling processes, that allow sediment to fall out of flows that are slowed and temporarily impounded in ponds, traps, or in small pools created by berms, silt fencing, inlet protection dikes, check dams, etc.Erosion prevention practices include 1) planning approaches that minimize the size of the bare soil area and the length of time disturbed areas are exposed to the elements – especially for long, steep slopes and easily erodible soils, 2) diverting or otherwise controlling the location and volume of run-on flows to the site from adjacent areas, 3)keeping concentrated flows in ditches stabilized with vegetation, rock, or other material, and 4)covering bare soil with vegetation, mulch, erosion control blankets, turf reinforcement mats, gravel, rock, plastic sheeting, soil binder chemicals, etc.Pollution prevention (P2) is a “front-end” method to decrease costs, risks, and environmental concerns. In contrast to managing pollution after it is created, P2 reduces or eliminates waste and pollution at its source. P2 includes a variety of residential, municipal, and industrial practices.imagemap for stormwater BMPs
Stormwater Best Management Practices. Mouse hover over an i box to read a description of the practice, or click on an i box to go to a page on the practice.

By type

By treatment mechanism

Regulatory, permitting

Models, calculations, methodologies, pollutant removal, credits

Case studies and examples

Communications and outreach

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Training and webinar schedule. Image: Microsoft stock image

Stormwater research and education

Reference

Documents










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This page was last edited on 2 October 2024, at 15:10.