The Minnehaha Creek Watershed District (MCWD) approved $211,000 for Low Impact Development (LID) funding for the incorporation of permeable pavers with infiltration tanks and bio-retention basins at St. Mary’s Greek Orthodox Church.

PROJECT LOCATION

3450 Irving Avenue South, Minneapolis, MN 55408

STORMWATER MANAGEMENT BMPs

• Existing flat rooftops for detention
• Five subsurface ‘soy based’ plastic storage chambers
• One subsurface corrugated metal storage reservoir
• One infiltration basin w/turf
• One detention basin w/turf
• Five bio-retention basins w/rain garden plants
• 3,550 square feet of permeable pavers

PEAK DISCHARGE

The site maintains peak discharge rates and volumes for pre-development conditions for the 1-year, 2-year, 10-year, and 100-year, 24-hour storm events. In addition, the as-built conditions meet the peak discharge rate and volume for the 10-year, 24-hour storm event under pre-settlement conditions.

WATER QUALITY AND VOLUME CONTROL

Through reducing impervious cover, pre-treatment devices, bio-retention, dead storage, and infiltration through engineered soils for significant volume reduction, the 70% TSS requirement is fulfilled and exceeded. A 30% phosphorous load reduction (Lake Calhoun) is fulfilled and exceeded based on the above proposed BMP’s, but more importantly due to a reduction from 0.053 af to 0.002 af of runoff (96.23%) for the 1-1/4” rain event.

Photos courtesy of Solution Blue