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Grading has been revised in this area: <br /> c. Piovide culverts beneath driveways: <br /> The applicant was planning otz providing culverts beizeath driveways to conizect Swale sections. These <br /> culverts are now shown on the Plan, where open section drainage is proposed. <br /> d. How will swale grades be reconciled with the grades of the intersecting pavements? <br /> See Plans. <br /> e. The parking area located within Lot 9 has uncontrolled sheet drainage at a grade.of 10%. <br /> The grading of this parkiizg area has been revised to direct the runoff to either a glass cli•ai/zage swale <br /> equipped with rip rap stabilization to the south or a paved gtttter to the north. Both conveyance facilities <br /> discharge to the grass channel that is located adjacent to Lettie Lade, which has a slope of less than 3% <br /> and eventually dischaiges to the bioretention area located within the entrance round-about. <br /> f. Much of the surface runoff from the commercial parkingwill not be intercepted and controlled <br /> by swales. Grading suggests it will be carried out the entrance to Route 130: There should be <br /> catchbasins.at the.entrance at Route 130 to collect runoff from entering the public way. <br /> ' <br /> .All solace ricnofffi-ona'the'com/nerciail parking lots will be collected and either infiltrated or discharged <br /> in a controlled manner, as to ensure public safety. Runoff will be collected by paved glitters and <br /> dischai-6ed to bioretetztion areas tdu ougli"rip rapped stabilized inflow channels. Due to the-Site being <br /> broken tip_into small drainage areas, bioretention facilities are sized to store and infiltrate-storms up to <br /> the 25 year, 24-hour storm during frozen ground conditions. Extreme storm events(i.e. 100-year storm) <br /> dtiring.hon-frozen conditions will be.controlled by etrieig-n ovetflowstructures, which discharge at a <br /> rate below the pre-developinent conditions. <br /> Tie have included two additional deep-sump catchbasins, at the entrance to Route 130, to collect any <br /> run Off not collected by the bioretention facility!proposed in the entrance cul-de-sac. These additional <br /> catchbasins will direct runoff to ci proposed recharge basin, as shown on the Plans. <br /> g. Two bioretention areas adjacent to the wastewater subsurface absorption areas (SAS). <br /> All bioretention areas maintain a 10 foot setback to the SAS systems, in accordance with Title 5. One <br /> bioretention area has been>elindnated. Also, the bioretention system close to the SAS systems is equipped <br /> with an tin'derdrain that will collect runoff and direct it to the large infiltration basil? or the southern <br /> portion of Site. <br /> h. Spot grades in commercial parldng.lots. <br /> Response Letter Horsley Witten Group <br /> Main Street Village(Lettie Lane)1vlashpee,MA 6 March,5,2004 <br /> Horsley Witten Group <br /> �Hf.'2ir2vl_r_.iV7!'Jt7irr.:r.Gi�:vrl,'%'J07S i�E <br />