Difference between revisions of "Case studies for infiltration"
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| − | {{alert| | + | [[File:Pdf image.png|100px|thumb|alt=pdf image|<font size=3>[https://stormwater.pca.state.mn.us/index.php?title=File:Case_studies_for_infiltration_-_Minnesota_Stormwater_Manual_July_2022.pdf Download pdf]</font size>]] |
| + | [[File:General information page image.png|left|100px|alt=image]] | ||
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| + | {{alert|Infiltration practices can be an important tool for retention and detention of stormwater runoff and treatment of pollutants in stormwater runoff. If the practice utilizes vegetation, additional benefits may include cleaner air, carbon sequestration, improved biological habitat, and aesthetic value.|alert-success}} | ||
Case studies of stormwater infiltration systems, including one underground system, are presented below. | Case studies of stormwater infiltration systems, including one underground system, are presented below. | ||
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[[File:Plan layout of infiltration and reuse systems.png|left|thumb|300 px|alt=This image shows a plan layout of infiltration and reuse systems|<font size=3>Plan layout of infiltration and reuse systems. Click on mage to enlarge.</font size>]] | [[File:Plan layout of infiltration and reuse systems.png|left|thumb|300 px|alt=This image shows a plan layout of infiltration and reuse systems|<font size=3>Plan layout of infiltration and reuse systems. Click on mage to enlarge.</font size>]] | ||
| − | [[File:Contech infiltration system in native sandy soils.png |right|thumb|300 px|alt=This picture shows a Contech infiltration system in native sandy soils|<font size=3> | + | [[File:Contech infiltration system in native sandy soils.png |right|thumb|300 px|alt=This picture shows a Contech infiltration system in native sandy soils|<font size=3>TrueNorthSteel infiltration system in native sandy soils</font size>]] |
| − | [[File:StormTrap underground storage vault for water stormwater reuse as irrigation.png|right|thumb|300 px|alt=This image shows a StormTrap underground storage vault for | + | [[File:StormTrap underground storage vault for water stormwater reuse as irrigation.png|right|thumb|300 px|alt=This image shows a StormTrap underground storage vault for stormwater reuse as irrigation|<font size=3>StormTrap underground storage vault for water stormwater reuse as irrigation.</font size>]] |
| − | In fall of 2015, [http://www.capitolregionwd.org/ Capitol Region Watershed District] (CRWD), in partnership with the City of Roseville and through two State of Minnesota grants, constructed a 60,000 cubic foot (450,000 gallon) underground stormwater infiltration system combined with a 13,000 cubic foot (100,000 gallon) modular concrete cistern to harvest and use stormwater for irrigation of a high-use softball field | + | In fall of 2015, [http://www.capitolregionwd.org/ Capitol Region Watershed District] (CRWD), in partnership with the City of Roseville and through two State of Minnesota grants, constructed a 60,000 cubic foot (450,000 gallon) underground stormwater <span title="Infiltration Best Management Practices (BMPs) treat urban stormwater runoff as it flows through a filtering medium and into underlying soil, where it may eventually percolate into groundwater. The filtering media is typically coarse-textured and may contain organic material, as in the case of bioinfiltration BMPs."> [https://stormwater.pca.state.mn.us/index.php?title=Stormwater_infiltration_Best_Management_Practices '''infiltration''']</span> system at Upper Villa Park in Roseville, Minnesota. The underground system was combined with a 13,000 cubic foot (100,000 gallon) modular concrete <span title="A waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater."> '''cistern'''</span> to <span title="Rain water harvesting is the practice of collecting rain water from impermeable surfaces, such as rooftops, and storing for future use."> '''[https://stormwater.pca.state.mn.us/index.php?title=Stormwater_and_rainwater_harvest_and_use/reuse harvest and use]'''</span> stormwater for irrigation of a high-use softball field. The underground infiltration system was comprised of a TrueNorthSteel CMP (Corrugated Metal Pipe) Detention System. The construction project will protect water quality within Lake McCarrons, a high quality recreational lake within the urban core of the Twin Cities, and the [http://www.capitolregionwd.org/watershed-information/water-resources-in-crwd/lakes/lake-mccarrons/vp/ Villa Park Wetland System] by capturing stormwater runoff and filtering pollutants associated with urban stormwater, such as total phosphorus (TP), total suspended solids (TSS), heavy metals, and petroleum products. |
| − | [ | + | <span title="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. Pretreatment practices include settling devices, screens, and pretreatment vegetated filter strips."> [https://stormwater.pca.state.mn.us/index.php?title=Pretreatment '''Pretreatment''']</span> to the underground infiltration basin is provided by a baffled sump <span title="A catch basin is an engineered drainage structure with the sole function of collecting rainwater and snowmelt from streets and parking lots and transporting it to local waterways through a system of underground piping, culverts, and / or drainage ditches"> '''catch basin'''</span>. The Preserver by Momentum Environmental provides settlement of suspended sediments and the capture of debris up stream of the infiltration system. Perforated baffles prevent resuspension and loss of fine sediments into the infiltration system. [[Pretreatment]] is consistent with the Minnesota Stormwater Manual guidance. |
In addition to removing approximately 45 pounds of TP annually, the system will save up to 1.3 million gallons of drinking water by capturing and using rainwater to irrigate the softball field in the park. | In addition to removing approximately 45 pounds of TP annually, the system will save up to 1.3 million gallons of drinking water by capturing and using rainwater to irrigate the softball field in the park. | ||
| − | In order to determine the effectiveness of infiltration practice pollutant removal, three custom-built pan-lysimeter wells were installed. Samples will be extracted from the wells and tested for a suite of pollutants and bacteria to determine the fate of these constituents once they leave the infiltration system on their way to groundwater resources. | + | In order to determine the effectiveness of infiltration practice pollutant removal, three custom-built pan-<span title="A lysimeter is a device or apparatus that measures water movement in the soil, edaphic or vadose zone."> '''lysimeter'''</span> wells were installed. Samples will be extracted from the wells and tested for a suite of pollutants and bacteria to determine the fate of these constituents once they leave the infiltration system on their way to groundwater resources. |
| − | CRWD has operated an automated ISCO sampler at the outflow of this 250-acre subwatershed since 2014. CRWD will continue to assess the effectiveness of the system by monitoring inflow, bypass, and levels within both the cistern and pipe gallery, and will sample upstream and downstream of the system in 2016. | + | CRWD has operated an automated ISCO sampler at the outflow of this 250-acre subwatershed since 2014. CRWD will continue to assess the effectiveness of the system by monitoring inflow, <span title="Stormwater runoff in excess of the design flow, which is diverted around a stormwater structure"> '''bypass flow'''</span>, and levels within both the cistern and pipe gallery, and will sample upstream and downstream of the system in 2016. |
The goal of this project is to protect water quality within Lake McCarrons and the Villa Park Wetland System by reducing stormwater volumes and annually removing 45 pounds of phosphorus. Secondary goals are to reduce drinking water as an irrigation source, determine the pollutant removal and groundwater protection capacity of infiltrating into native sands, and to optimize volume reduction by utilizing real time controls based on weather forecasts. | The goal of this project is to protect water quality within Lake McCarrons and the Villa Park Wetland System by reducing stormwater volumes and annually removing 45 pounds of phosphorus. Secondary goals are to reduce drinking water as an irrigation source, determine the pollutant removal and groundwater protection capacity of infiltrating into native sands, and to optimize volume reduction by utilizing real time controls based on weather forecasts. | ||
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[[File:Finished basin with simple groupings of shrubs grasses and trees.png |right|thumb|300 px|alt=This picture shows a finished basin with simple groupings of shrubs grasses and trees|<font size=3>Finished basin with simple groupings of shrubs grasses and trees</font size>]] | [[File:Finished basin with simple groupings of shrubs grasses and trees.png |right|thumb|300 px|alt=This picture shows a finished basin with simple groupings of shrubs grasses and trees|<font size=3>Finished basin with simple groupings of shrubs grasses and trees</font size>]] | ||
| − | The City of Minneapolis hired Barr Engineering to design stormwater | + | The City of Minneapolis hired Barr Engineering to design stormwater <span title="One of many different structural or non–structural methods used to treat runoff"> '''best management practice'''</span> (BMPs) along Riverside Avenue in conjunction with a street reconstruction project, which added bike lanes, parking, designated turn lanes, and center medians. Design and construction took place between 2011 and 2013. |
| − | The 8th Street infiltration basin was constructed at the intersection of Riverside Avenue and 8th Street where Riverside crossed at an angle, resulting in an awkward intersection and an unbuildable triangular piece of property. The intersection was redesigned to align 8th Street through the unused triangular property to create a standard perpendicular intersection. Bisecting the property allowed for the creation of two BMPs on either side of 8th Street. On one side there is a stormwater infiltration basin with a curved concrete retaining wall and railing. Trees and grasses were planted at the bottom while shrubs on the side slopes frame the basin. On the opposite side of 8th Street there is a plaza with | + | The 8th Street infiltration basin was constructed at the intersection of Riverside Avenue and 8th Street where Riverside crossed at an angle, resulting in an awkward intersection and an unbuildable triangular piece of property. The intersection was redesigned to align 8th Street through the unused triangular property to create a standard perpendicular intersection. Bisecting the property allowed for the creation of two BMPs on either side of 8th Street. On one side there is a stormwater infiltration basin with a curved concrete retaining wall and railing. Trees and grasses were planted at the bottom while shrubs on the side slopes frame the basin. On the opposite side of 8th Street there is a plaza with <span title="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)."> '''[https://stormwater.pca.state.mn.us/index.php?title=Permeable_pavement permeable pavers]'''</span> over a stormwater <span title="A tree trench, often known as a "vertical rain garden," is a system that consists of piping for water storage, structural soils and a tree."> '''[https://stormwater.pca.state.mn.us/index.php?title=Trees tree trench]'''</span> (modified Swedish tree trenches) consisting of layers of crushed stone and soil to provide stormwater storage and growing media for the trees. BMPs on both sides of 8th Street are connected with an equalizer pipe. A stone sitting bench completes the pedestrian-friendly plaza. The 8th Street BMPs are expected to capture and treat 0.5 inches of runoff from 2.2 acres of tributary area. |
The goals of this green infrastructure project are: | The goals of this green infrastructure project are: | ||
*treating stormwater runoff to remove sediments and other pollutants; | *treating stormwater runoff to remove sediments and other pollutants; | ||
| − | *infiltrating significant portions the contributing drainage area runoff; | + | *infiltrating significant portions of the <span title="The total drainage area, including pervious and impervious surfaces, contributing to a BMP"> '''[https://stormwater.pca.state.mn.us/index.php?title=Contributing_drainage_area_to_stormwater_BMPs contributing drainage area]'''</span> runoff; |
*increasing the amount of pervious surface in the right of way; | *increasing the amount of pervious surface in the right of way; | ||
*providing a non-irrigated water source to the proposed trees and plantings; and | *providing a non-irrigated water source to the proposed trees and plantings; and | ||
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==Rosetown American Legion Post 542 Infiltration Basin== | ==Rosetown American Legion Post 542 Infiltration Basin== | ||
| − | [[File:Plan and section view of the infiltration basin.png |left|thumb|300 px|alt=This picture shows a plan and section view of the infiltration basin|<font size=3>Plan and section view of the infiltration basin</font size>]] | + | [[File:Plan and section view of the infiltration basin.png |left|thumb|300 px|alt=This picture shows a plan and section view of the infiltration basin|<font size=3>Plan and section view of the infiltration basin. Click on image to enlarge.</font size>]] |
| − | [[File:Modular Block Sediment Trap.png |right|thumb|300 px|alt=This picture shows a Modular Block Sediment Trap|<font size=3>Modular Block Sediment Trap</font size>]] | + | [[File:Modular Block Sediment Trap.png |right|thumb|300 px|alt=This picture shows a Modular Block Sediment Trap|<font size=3>Modular Block Sediment Trap for pretreatment.</font size>]] |
[[File:Infiltration basin with rough grading complete.png|thumb|300 px|alt=This image picture show an Infiltration basin with rough grading complete|<font size=3>Infiltration basin with rough grading complete</font size>]] | [[File:Infiltration basin with rough grading complete.png|thumb|300 px|alt=This image picture show an Infiltration basin with rough grading complete|<font size=3>Infiltration basin with rough grading complete</font size>]] | ||
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For preconstruction investigations, an 18 foot soil boring was used to identify sandy gravel soils. There was no confining layer of less permeable subsoils identified. The basin was sized to collect the 1.1 inch storm event off the parking lot and surrounding sidewalks. The basin was graded to store water no deeper than 12 inches below the gutter flow line. The curb cut was positioned at the lowest possible downstream side of the curb. Surrounding slopes within the basin were designed to be no greater than 4:1. | For preconstruction investigations, an 18 foot soil boring was used to identify sandy gravel soils. There was no confining layer of less permeable subsoils identified. The basin was sized to collect the 1.1 inch storm event off the parking lot and surrounding sidewalks. The basin was graded to store water no deeper than 12 inches below the gutter flow line. The curb cut was positioned at the lowest possible downstream side of the curb. Surrounding slopes within the basin were designed to be no greater than 4:1. | ||
| − | [ | + | <span title="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. Pretreatment practices include settling devices, screens, and pretreatment vegetated filter strips."> [https://stormwater.pca.state.mn.us/index.php?title=Pretreatment '''Pretreatment''']</span> for the infiltration basin is provided by a curb cut with a modular block step-down structure. Stormwater flows down the block steps and into a shallow sump feature akin to a small <span title="An artificial pool of water in front of a larger body of water. The larger body of water may be natural or man-made. Forebays have a number of functions. They may be used upstream of reservoirs to trap sediment and debris (sometimes called a sediment forebay) in order to keep the reservoir clean."> '''[https://stormwater.pca.state.mn.us/index.php?title=Pretreatment_-_Screening_and_straining_devices,_including_forebays forebay]'''</span>. The energy of the stormwater is dissipated to prevent scouring or erosion while sediments are allowed to drop out for easy collection later. The pretreatment sump is not sized per [http://stormwater.pca.state.mn.us/index.php/Overview_for_pretreatment_settling_devices#Water_quality_treatment current Stormwater Manual recommendations] that the forebay be approximately 10 percent the size of the infiltration basin. |
The infiltration basin was designed to have ornamental grasses, including ‘Heavy Metal’ Switchgrass (Panicum virgatum ‘Heavy Metal’), low shrubs including low bush honeysuckle (Diervilla Lonicera) , natives sedges such as tussock sedge (Carex stricta) and native forbs such as Joe Pye Weed (Eutrochium purpurem). | The infiltration basin was designed to have ornamental grasses, including ‘Heavy Metal’ Switchgrass (Panicum virgatum ‘Heavy Metal’), low shrubs including low bush honeysuckle (Diervilla Lonicera) , natives sedges such as tussock sedge (Carex stricta) and native forbs such as Joe Pye Weed (Eutrochium purpurem). | ||
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The Rosetown American Legion Post 542 infiltration basin has been included as one of several projects being maintained as part of the Ramsey-Washington Metro Watershed District BMP Maintenance Program. As part of the maintenance program, the site is inspected monthly during the growing season by a contractor. The site is assessed for any erosion, trash, weeds and sediment depths in the modular block splash block assemblies. The required time for crews to remove and dispose of materials is recorded and time and expenses are paid for. Contractor crews also look for any plant damage or soil conditions that would indicate slow drainage. Budgets for maintenance of the site are adjusted yearly. | The Rosetown American Legion Post 542 infiltration basin has been included as one of several projects being maintained as part of the Ramsey-Washington Metro Watershed District BMP Maintenance Program. As part of the maintenance program, the site is inspected monthly during the growing season by a contractor. The site is assessed for any erosion, trash, weeds and sediment depths in the modular block splash block assemblies. The required time for crews to remove and dispose of materials is recorded and time and expenses are paid for. Contractor crews also look for any plant damage or soil conditions that would indicate slow drainage. Budgets for maintenance of the site are adjusted yearly. | ||
| − | In the spring, all the previous year’s vegetation from the perennials, sedges and grasses is removed and disposed of. The shrubs are pruned for proper form and to remove any dead branches. As mulch decomposes, its depth is refreshed to maintain approximately 3 inches of shredded hardwood mulch throughout the basin. | + | In the spring, all the previous year’s vegetation from the <span title="A perennial plant or simply perennial is a plant that lives more than two years"> '''perennials'''</span>, sedges and grasses is removed and disposed of. The shrubs are pruned for proper form and to remove any dead branches. As mulch decomposes, its depth is refreshed to maintain approximately 3 inches of shredded hardwood mulch throughout the basin. |
:'''Location:''' Roseville, MN | :'''Location:''' Roseville, MN | ||
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:'''Designer:''' Barr Engineering Company | :'''Designer:''' Barr Engineering Company | ||
:'''Year of Completion:''' 2015 | :'''Year of Completion:''' 2015 | ||
| − | :'''Design Features:''' Bioinfiltration basin | + | :'''Design Features:''' <span title="A bioretention practice in which no underdrain is used. All water entering the bioinfiltration practice infiltrates or evapotranspires."> '''Bioinfiltration'''</span> basin |
:'''Total Drainage Area:''' 0.85 Acres | :'''Total Drainage Area:''' 0.85 Acres | ||
:'''Total Construction Cost''': $47,000 | :'''Total Construction Cost''': $47,000 | ||
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<noinclude> | <noinclude> | ||
| + | |||
==Related pages== | ==Related pages== | ||
*[http://stormwater.pca.state.mn.us/index.php/Infiltration Infiltration portal] | *[http://stormwater.pca.state.mn.us/index.php/Infiltration Infiltration portal] | ||
| − | |||
*[[Overview for infiltration]] | *[[Overview for infiltration]] | ||
*[[BMPs for stormwater infiltration|Types of infiltration]] | *[[BMPs for stormwater infiltration|Types of infiltration]] | ||
| Line 120: | Line 123: | ||
*[[References for infiltration]] | *[[References for infiltration]] | ||
*[[Requirements, recommendations and information for using infiltration basin/underground infiltration BMPs in the MIDS calculator]] | *[[Requirements, recommendations and information for using infiltration basin/underground infiltration BMPs in the MIDS calculator]] | ||
| − | |||
*[[Understanding and interpreting soils and soil boring reports for infiltration BMPs]] | *[[Understanding and interpreting soils and soil boring reports for infiltration BMPs]] | ||
*[[Determining soil infiltration rates]] | *[[Determining soil infiltration rates]] | ||
*Cold climate considerations for infiltration practices - See [http://stormwater.pca.state.mn.us/index.php/Cold_climate_impact_on_runoff_management#Infiltration], [http://stormwater.pca.state.mn.us/index.php/Cold_climate_impact_on_runoff_management#Infiltration_practices] | *Cold climate considerations for infiltration practices - See [http://stormwater.pca.state.mn.us/index.php/Cold_climate_impact_on_runoff_management#Infiltration], [http://stormwater.pca.state.mn.us/index.php/Cold_climate_impact_on_runoff_management#Infiltration_practices] | ||
| + | |||
| + | [[Category:Level 3 - Case studies and examples/Case studies/BMPs]] | ||
</noinclude> | </noinclude> | ||
Latest revision as of 20:15, 12 December 2022
Case studies of stormwater infiltration systems, including one underground system, are presented below.
Contents
Upper Villa Park Infiltration and Reuse, Capitol Region Watershed District, SRF Consulting Group, Inc., City of Roseville
In fall of 2015, Capitol Region Watershed District (CRWD), in partnership with the City of Roseville and through two State of Minnesota grants, constructed a 60,000 cubic foot (450,000 gallon) underground stormwater infiltration system at Upper Villa Park in Roseville, Minnesota. The underground system was combined with a 13,000 cubic foot (100,000 gallon) modular concrete cistern to harvest and use stormwater for irrigation of a high-use softball field. The underground infiltration system was comprised of a TrueNorthSteel CMP (Corrugated Metal Pipe) Detention System. The construction project will protect water quality within Lake McCarrons, a high quality recreational lake within the urban core of the Twin Cities, and the Villa Park Wetland System by capturing stormwater runoff and filtering pollutants associated with urban stormwater, such as total phosphorus (TP), total suspended solids (TSS), heavy metals, and petroleum products.
Pretreatment to the underground infiltration basin is provided by a baffled sump catch basin. The Preserver by Momentum Environmental provides settlement of suspended sediments and the capture of debris up stream of the infiltration system. Perforated baffles prevent resuspension and loss of fine sediments into the infiltration system. Pretreatment is consistent with the Minnesota Stormwater Manual guidance.
In addition to removing approximately 45 pounds of TP annually, the system will save up to 1.3 million gallons of drinking water by capturing and using rainwater to irrigate the softball field in the park.
In order to determine the effectiveness of infiltration practice pollutant removal, three custom-built pan- lysimeter wells were installed. Samples will be extracted from the wells and tested for a suite of pollutants and bacteria to determine the fate of these constituents once they leave the infiltration system on their way to groundwater resources.
CRWD has operated an automated ISCO sampler at the outflow of this 250-acre subwatershed since 2014. CRWD will continue to assess the effectiveness of the system by monitoring inflow, bypass flow, and levels within both the cistern and pipe gallery, and will sample upstream and downstream of the system in 2016.
The goal of this project is to protect water quality within Lake McCarrons and the Villa Park Wetland System by reducing stormwater volumes and annually removing 45 pounds of phosphorus. Secondary goals are to reduce drinking water as an irrigation source, determine the pollutant removal and groundwater protection capacity of infiltrating into native sands, and to optimize volume reduction by utilizing real time controls based on weather forecasts.
Estimates for total annual volume reduction (1,330,000 cubic feet, 10 million gallons), TP removal (45 pounds) and potable water use reduction (174,000 cubic feet, 1.3 million gallons) will be verified with monitoring data.
For more information, visit CRWD's project site page.
- Location: Roseville, MN
- Owners: City of Roseville and Capitol Region Watershed District
- Designer: SRF Consulting Group Inc.
- Year of Completion: 2015
- Design Features: underground stormwater infiltration system, modular concrete cistern for water reuse as irrigation
- Total Drainage Area: 250 Acres
- Total Construction Cost: $861,500
- Pretreatment: The Preserver (Momentum Environmental) baffled sump catch basin
- Documented Maintenance Practices: Inspection, sediment depth measurements, sediment removal and disposal
- Pollutant Removal: 45 lb/yr total phosphorus removed
- Is the Site Publicly Accessible: Yes
Riverside Stormwater Park, City of Minneapolis
The City of Minneapolis hired Barr Engineering to design stormwater best management practice (BMPs) along Riverside Avenue in conjunction with a street reconstruction project, which added bike lanes, parking, designated turn lanes, and center medians. Design and construction took place between 2011 and 2013.
The 8th Street infiltration basin was constructed at the intersection of Riverside Avenue and 8th Street where Riverside crossed at an angle, resulting in an awkward intersection and an unbuildable triangular piece of property. The intersection was redesigned to align 8th Street through the unused triangular property to create a standard perpendicular intersection. Bisecting the property allowed for the creation of two BMPs on either side of 8th Street. On one side there is a stormwater infiltration basin with a curved concrete retaining wall and railing. Trees and grasses were planted at the bottom while shrubs on the side slopes frame the basin. On the opposite side of 8th Street there is a plaza with permeable pavers over a stormwater tree trench (modified Swedish tree trenches) consisting of layers of crushed stone and soil to provide stormwater storage and growing media for the trees. BMPs on both sides of 8th Street are connected with an equalizer pipe. A stone sitting bench completes the pedestrian-friendly plaza. The 8th Street BMPs are expected to capture and treat 0.5 inches of runoff from 2.2 acres of tributary area.
The goals of this green infrastructure project are:
- treating stormwater runoff to remove sediments and other pollutants;
- infiltrating significant portions of the contributing drainage area runoff;
- increasing the amount of pervious surface in the right of way;
- providing a non-irrigated water source to the proposed trees and plantings; and
- enhancing beauty and functionality of public space.
- Location: Minneapolis, MN
- Owners: City of Minneapolis
- Designer: Barr Engineering Company
- Year of Completion: 2013
- Design Features: Tree planter boxes, permeable pavers, surface and underground storage, raingardens, depressed boulevards
- Pretreatment Features: Water quality catch basin with sumps for sediment capture meeting current Stormwater Manual guidance
- Total Drainage Area: 2.2 Acres
- Total Construction Cost: $153,000
- Documented Maintenance Practices: Inspection, herbicide/pesticide treatments, weeding, trimming, plant and tree replacement
- Pollutant Removal: 1.0 lb/yr Dissolved Phosphorus removed, 407 lb/yr TSS removed.
- Is the Site Publicly Accessible: Yes.
Rosetown American Legion Post 542 Infiltration Basin
As part of a watershed properties study of commercial parcels begun in 2014, Ramsey-Washington Metro Watershed District identified green space adjacent to the parking lot of the Rosetown American Legion Post 542 in Roseville, Minnesota. An unused turf area was targeted for a commercially sized infiltration basin. Collaborating with the American Legion leadership, the project was constructed in 2015 as part of a series of BMPs identified during the initial watershed properties study.
For preconstruction investigations, an 18 foot soil boring was used to identify sandy gravel soils. There was no confining layer of less permeable subsoils identified. The basin was sized to collect the 1.1 inch storm event off the parking lot and surrounding sidewalks. The basin was graded to store water no deeper than 12 inches below the gutter flow line. The curb cut was positioned at the lowest possible downstream side of the curb. Surrounding slopes within the basin were designed to be no greater than 4:1.
Pretreatment for the infiltration basin is provided by a curb cut with a modular block step-down structure. Stormwater flows down the block steps and into a shallow sump feature akin to a small forebay. The energy of the stormwater is dissipated to prevent scouring or erosion while sediments are allowed to drop out for easy collection later. The pretreatment sump is not sized per current Stormwater Manual recommendations that the forebay be approximately 10 percent the size of the infiltration basin.
The infiltration basin was designed to have ornamental grasses, including ‘Heavy Metal’ Switchgrass (Panicum virgatum ‘Heavy Metal’), low shrubs including low bush honeysuckle (Diervilla Lonicera) , natives sedges such as tussock sedge (Carex stricta) and native forbs such as Joe Pye Weed (Eutrochium purpurem).
The infiltration basin cost $47,000, treats 1,100 cubic feet of stormwater and is estimated to remove 262 pounds of TSS and 0.57 pounds of dissolved P per year.
The Rosetown American Legion Post 542 infiltration basin has been included as one of several projects being maintained as part of the Ramsey-Washington Metro Watershed District BMP Maintenance Program. As part of the maintenance program, the site is inspected monthly during the growing season by a contractor. The site is assessed for any erosion, trash, weeds and sediment depths in the modular block splash block assemblies. The required time for crews to remove and dispose of materials is recorded and time and expenses are paid for. Contractor crews also look for any plant damage or soil conditions that would indicate slow drainage. Budgets for maintenance of the site are adjusted yearly.
In the spring, all the previous year’s vegetation from the perennials, sedges and grasses is removed and disposed of. The shrubs are pruned for proper form and to remove any dead branches. As mulch decomposes, its depth is refreshed to maintain approximately 3 inches of shredded hardwood mulch throughout the basin.
- Location: Roseville, MN
- Owners: Ramsey-Washington Metro Watershed District
- Designer: Barr Engineering Company
- Year of Completion: 2015
- Design Features: Bioinfiltration basin
- Total Drainage Area: 0.85 Acres
- Total Construction Cost: $47,000
- Documented Maintenance Practices: Inspection, herbicide/pesticide treatments, weeding, trimming, removal of sediment from sump step down structure
- Pollutant Removal: 0.57 lb/yr Dissolved Phosphorus removed, 262 lb/yr TSS removed.
- Is the Site Publicly Accessible: Yes but on private property
Related pages
- Infiltration portal
- Overview for infiltration
- Types of infiltration
- Design criteria for infiltration
- Construction specifications for infiltration
- Operation and maintenance of stormwater infiltration practices
- Assessing the performance of infiltration
- Calculating credits for infiltration
- Cost-benefit considerations for infiltration
- Case studies for infiltration
- External resources for infiltration
- References for infiltration
- Requirements, recommendations and information for using infiltration basin/underground infiltration BMPs in the MIDS calculator
- Understanding and interpreting soils and soil boring reports for infiltration BMPs
- Determining soil infiltration rates
- Cold climate considerations for infiltration practices - See [1], [2]
This page was last edited on 12 December 2022, at 20:15.