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NA <br />Dr,.iinage Arf :j <br />2% MAX. <br />Ml ix. Slope <br />3 ff <br />Min. Depth to Bedrock <br />3 ft <br />Min. Depth to Water Table <br />SCS Soil Type <br />A,B: <br />nc ;nh. r111,- l •:Icer!!,: <br />GOOD <br />Freeze/ Thaw Suitability <br />- <br />,%,dh aC1C[pwlC ' <br />Potential Notspot Runoff <br />YES <br />`rogelires imoormeohle 1iner it donhfir 1 ri hoisi;ol <br />"r,F, <br />Description: <br />Pervious pavements can be subdivided into three <br />general categories: 1) Porous Pavements — porous <br />surfaces that infiltrate water across the entire surface <br />(i.e. porous asphalt and porous concrete pavements); <br />2) Permeable Pavers — impermeable modular blocks <br />or grids separated by spaces or joints that water <br />drains through (i.e. block pavers, plastic grids, etc.); <br />3) Amended Soils - Fiber or artificial media added to <br />soil to maintain soil structure and prevent compaction. <br />There are many different types of modular porous <br />pavers available from different manufacturers. <br />Pervious pavement systems reduce runoff from <br />impervious surfaces by allowing storm water to pass <br />through the load bearing surface and infill that are <br />selected based upon the intended application and <br />required infiltration rate. Runoff is stored in the stone <br />aggregate base course/ storage layer, if present, and <br />allowed to infiltrate into the surrounding soil (functioning <br />like an infiltration basin), or collected by an under -drain <br />system and discharged to the storm sewer system or <br />directly to receiving waters (functioning like a surface <br />sand filter). <br />Regular maintenance of pervious pavements is <br />necessary to ensure long-term effectiveness. Annual or <br />semi-annual sweeping or vacuuming of surface debris <br />(litter, sediment, etc.) is STRONGLY RECOMMENDED <br />for pavement or pavers. If clogging occurs, the filtration <br />media below the surface may need to be replaced. <br />Manufacturers should be consulted for specific <br />maintenance requirements. <br />Currently, the NIPCA will allow site designers to reduce <br />the water quality volume sizing when using pervious <br />pavement, up to a maxim Urn of 1/2 acre of new impervious <br />surface. The MPCA will not allow pervious pavements <br />as a replacement for water quality treatment BMPs, <br />such as infiltration or filtration practices. <br />Start of Storm Event - Initial runoff & storage <br />Duration of Storm Event- Storage & filtration/infiltration <br />Storm Event - <br />r <br />a raw -a own <br />4 Y. <br />AN lLinlm e�ki.i � ni.r n'+ .. rtiw�,t . <br />tdi' t RZ'- 1P - llt tni 511 — <br />F{! <br />