HomeMy WebLinkAbout2020-01-27 Peak Runoff Rates & Volumes SPR HANCOCK ASSOCIATES Surveyors I Engineers I Scientists 22587 TRUSTEES—THE COOLIDGE ESTATE VISITORS' CENTER The following tables compare the peak rates of runoff and peak volumes under the existing and proposed conditions: PEAK RUNOFF RATES: Discharge 2-Year Storm 10-Year Storm 25-Year Storm 100-Year Storm Point (3.20"Rainfall Depth) (4.80"Rainfall Depth) (6.0"Rainfall Depth) (8.60"Rainfall Depth) Existing(cfs) Proposed(cfs) Existing(cfs) Proposed(cfs) Existing(efs.) Proposed(cfs.) Existing(efs.) Proposed(efs) DPI 3.4 1.0 8.1 5.0 12.1 8.2 21.4 16.2 PEAK VOLUMES: Discharge 2-Year Storm 10-Year Storm 25-Year Storm 100-Year Storm Point (3.20"Rainfall Depth) (4.80"Rainfall Depth) (6.0"Rainfall Depth) (8.60"Rainfall Depth) Existing Proposed Existing Proposed Existing Proposed Existing Proposed (Ac-ft) (Ac-ft) (AFft) (Ac-ft) (Ac-ft) (Ac-ft.) (Ac-ft) (Ac-ft) DPI 0.5 0.2 1.2 0.8 1.7 1.4 3.1 2.7 185 Centre Street I Danvers, MA 01923 V: 978-777-3050 ( F.978-774-7816 1 HancockAssociates.com ��- �rC'�r-,pr, n' iv C'9C nen_�' �r-,�r�.{ 1/] `fir�•.n1Rl lQvO�rl- �C�i'�I%'-=�r�Vr nfiA ' C41 =k,', v