m |
m |
||
Line 82: | Line 82: | ||
[https://stormwater.pca.state.mn.us/index.php?title=Permeable_pavement Link to permeable pavement] | [https://stormwater.pca.state.mn.us/index.php?title=Permeable_pavement Link to permeable pavement] | ||
+ | ==Tree trench system/box without underdrain== | ||
+ | [[File:Symbol for tree trench.png|300px|thumb|alt=Symbol for tree trench system-treebox|<font size=3>Symbol used for the tree trench system/box (w/o underdrain) BMP in the MIDS calculator. Note the symbol shows multiple trees since tree trench systems contain multiple trees.</font size>]] | ||
+ | *Applicability | ||
+ | **This is a good BMP in highly urban and ultra-urban settings | ||
+ | **Water is stored in the media instead of being ponded. Thus, the amount of water stored is less than bioinfiltration or infiltration basin per unit volume because solids are taking up some of the available storage space | ||
+ | **Diverse BMP that can be incorporated into many landscapes; provides multiple benefits (e.g. habitat, aesthetics) | ||
+ | *Volume retention | ||
+ | **This is typically an underground BMP, so the system could be designed to maximize volume retention by maximizing either area or depth | ||
+ | **Volume retention increase with tree size (evapotranspiration), but make sure the tree size is practical for the site | ||
+ | **Determine the soil volume needed to maximize tree growth. This can be done by entering the number of trees in the appropriate cell in the calculator and examining the cells displaying volume reduction for ET and the soil volume per tree. Enter the tree number that maximizes ET while maximizing soil volume per tree. | ||
+ | **Coniferous trees increase ET and canopy interception (Note: they must be suitable for the site) | ||
− | + | [https://stormwater.pca.state.mn.us/index.php?title=Trees Link to information on tree trenches] | |
− | + | ||
− | + | ==Tree trench system/box with underdrain== | |
− | + | [[File:Symbol for tree trench with underdrain.jpg|300px|thumb|alt=symbol for tree trench system-treebox with underdrain|<font size=3>Symbol used in the MIDS calculator to represent the tree trench system-tree box BMP with an underdrain. Note the symbol shows multiple trees since tree trench systems contain multiple trees.</font size>]] | |
− | + | ||
− | + | *Applicability | |
− | + | **This is a good BMP in highly urban and ultra-urban settings | |
− | + | **Water is stored in the media instead of being ponded. Thus, the amount of water stored is less than bioinfiltration or infiltration basin per unit volume because solids are taking up some of the available storage space | |
− | + | **Diverse BMP that can be incorporated into many landscapes; provides multiple benefits (e.g. habitat, aesthetics) | |
− | + | *Volume retention | |
− | + | **This is typically an underground BMP, so the system could be designed to maximize volume retention by maximizing either area or depth | |
− | a | + | **Volume retention increase with tree size (evapotranspiration), but make sure the tree size is practical for the site |
− | + | **Determine the soil volume needed to maximize tree growth. This can be done by entering the number of trees in the appropriate cell in the calculator and examining the cells displaying volume reduction for ET and the soil volume per tree. Enter the tree number that maximizes ET while maximizing soil volume per tree. | |
− | + | **Coniferous trees increase ET and canopy interception (Note: they must be suitable for the site) | |
− | + | **Phosphorus | |
− | + | ***Use Mix C or D to maximize phosphorus removal. Mixes A and B require testing and will likely fail the test. | |
− | + | ***Incorporate iron into the system | |
− | + | ||
− | + | [https://stormwater.pca.state.mn.us/index.php?title=Trees Link to information on tree trenches] | |
− | + | ||
− | + | ==Swales== | |
− | + | [[File:Symbol for swale with no underdrain.png|300px|thumb|alt=symbol for swale with no underdrain|<font size=3>Symbol for Swale main channel (without an underdrain) used in the MIDS calculator.</font size>]] | |
− | + | [[File:Symbol for swale side slope.jpg|300px|thumb|alt=Schematic used as a symbol for swale side slope|<font size=3>Symbol for Swale side slope used in the MIDS calculator</font size>]] | |
− | + | ||
− | + | *Applicability | |
− | + | *Swale side slope and swale main channel (with or without underdrain) act as a single BMP. Make sure impervious and pervious acres are applied to the side slope and not the main channel, unless water is routed directly to a main channel. Swale lengths for side slopes and main channel should be the same for a swale system | |
− | + | **Diverse BMP that can be incorporated into many landscapes; provides multiple benefits (e.g. habitat, aesthetics) | |
− | + | **Not a good volume retention practice unless on A soils and/or designed with check dams or bioretention base | |
− | + | **Not good for highly urban and ultra-urban settings | |
− | a | + | *Volume retention |
− | + | **Increase swale length to maximize volume retention | |
− | + | **Check dams are the most effective way of capturing and infiltrating water on permeable soils | |
− | + | **Adding a bioretention base increase infiltration if underlying soils are permeable | |
− | + | **Increasing the channel slope reduces infiltration | |
− | + | ||
− | + | [https://stormwater.pca.state.mn.us/index.php?title=Dry_swale_(Grass_swale) Link to information on swales] | |
− | + | ||
− | + | ==Harvest and reuse/cistern== | |
+ | [[File:Symbol used for harvest and reuse.jpg|thumb|300px|alt=symbol for harvest and reuse in the MIDS calculator|<font size=3>MIDS calculator symbol for harvest and reuse.</font size>]] | ||
+ | |||
+ | *Applicability | ||
+ | **It is difficult to meet the retention requirement with this BMP | ||
+ | **Useful on low permeability soils for reducing the volume delivered to downstream BMPs | ||
+ | **Can be used in ultra-urban areas where there are small green spaces to irrigate | ||
+ | **Most effective when there are large green spaces that can be irrigated | ||
+ | *Volume retention | ||
+ | **If there is sufficient space on the site, ponds allow for greater volume storage. Volume reductions with cisterns are typically limited by the storage capacity of the cistern. | ||
+ | **To maximize volume reduction, maximize the volume application area | ||
+ | **On A soils you can apply up to 2 inches per week. This will exceed plant demand but because of the permeable soils, excess water will infiltrate. On other soils, to maximize volume reduction, choose “No” for the question asking about a user-defined irrigation rate. | ||
+ | **For vegetation, volume retention follows this order: Trees > turf = vegetables > forage > cereals | ||
+ | **Retaining water on-site typically has a small effect on volume retention | ||
+ | |||
+ | [https://stormwater.pca.state.mn.us/index.php?title=Stormwater_and_rainwater_harvest_and_use/reuse Link to information on stormwater harvest and reuse] | ||
+ | |||
+ | ==Stormwater disconnection== | ||
+ | [[File:Symbol for Stormwater Disconnection in MIDS calculator.png|right|thumb|300 px|alt=This image shows a symbol for Stormwater Disconnection in MIDS calculator|<font size=3>Symbol for Stormwater Disconnection in MIDS calculator</font size>]] | ||
+ | |||
+ | *Applicability | ||
+ | **Cannot be used to meet the Construction Stormwater permit volume retention requirement | ||
+ | **It is difficult to meet the retention requirement with this BMP | ||
+ | **Useful on low permeability soils for reducing the volume delivered to downstream BMPs | ||
+ | **Limited by the area that can effectively infiltrate water (see diagram on BMP Parameters tab for this BMP in the calculator) | ||
+ | *Volume retention | ||
+ | **Maximize the impervious area delivering water to the practice | ||
+ | **Maximize the pervious area (NOTE: this cannot exceed the pervious acres entered in the Watershed tab for this BMP) | ||
+ | |||
+ | [https://stormwater.pca.state.mn.us/index.php?title=Turf Link to information on stormwater impervious disconnection] | ||
+ | |||
+ | ==Wet swale, sand filter, constructed wetland, and constructed pond== | ||
+ | These BMPs do not reduce volume |
This page provides information and recommendations for maximizing volume retention in the MIDS calculator.
Link to infiltration basin/trench
Link to infiltration basin/trench
Link to information on tree trenches
Link to information on tree trenches
Link to information on stormwater harvest and reuse
Link to information on stormwater impervious disconnection
These BMPs do not reduce volume