Stormwater Quality Design Manual (May 2007) - City of Sacramento ...

Runoff Reduction Control Measure Fact SheetPorous PavementFigure PP-2. ModularBlockPavement,TypicalSection*(Source: adaptedfrom Denver)*Installationspecificationsmay vary by site;check with localpermittingagencyWrap all geofabric or impermeable liners up the sidesto top of pavement. Secure firmly in place.Woven geotextile fabric meeting:ASTM D4751-AOS of 50-70ASTM D4633 min. trapezoidal tear strength 100 x 60 lbs.Minimum COE specified open area of 4%.When Type C soils are present and when infiltration is allowed,unless permeability tests show otherwise, use underdrains andgeotextile liner specified above.When the underlying soils are Type D or expansive, useunderdrains and 16 mil minimum thickness impermeable liner underand on sides of the pavement sand & gravel media basin.Reinforced Grass PavementReinforced grass pavement (Figure PP-3) consistsof an irrigated surface, typically stabilized with amanufactured product over which soil and seed mixis spread. Of the various porous pavement options,this may provide the greatest stormwater qualitybenefit due to its high permeability andevapotranspiration and nutrient uptake byvegetation. This pavement type is well suited inlow-traffic areas, such as overflow parking areas(stalls can be marked with athletic field paint) andmaintenance roads. (Source: NEMO). However, itis not suitable for fire access lanes. Load bearingcapacity varies by product, so select thereinforcement grid based on anticipated load.Because of the reinforcement, the area can be usedeven when the ground is saturated. Irrigation isrequired to maintain the vegetation. Refer to Table PP-1 for design criteria for this type of porouspavement.Other names: grid pavers, green parking, GrasspaveNew installation of reinforced grass pavement.Photo: Puget Sound Action Team, WAStormwater Quality Design Manual for the Sacramento and South Placer RegionsMay 2007PP-7