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HomeMy WebLinkAboutAppendix M - Preliminary Technical Hydrology and Hydraulics ReportMethodology Used The San Bernardino County Hydrology Manual was used to determine the run-off peak flowrate for storm drain produced by the 100 -year storm event when comparing the existing and proposed conditions. All calculations are in accordance with the San Bernardino County Hydrology Manual and Technical Guidance Document for Water Quality Management. Based on WebSoilSurvey database, the proposed site is comprised of mainly Chino Silt Loam, which is classified as hydrologic soil group C. Refer to Appendix E for more in formation. Summary Per the San Bernardino County Hydrology Manual, a hydrology analysis has been completed for the 100 -year storm events for the proposed conditions. The post construction run-off is less than the pre-construction run-off, as shown in Appendix D . There is no additional impact to the downstream facilities. I n fact, the addition of an onsite water quality retention system will further reduce peak flows. Therefore, no additional stormwater infrastructure is necessary as a part of the Fontana Warehouse development. Refer to Appendix A for the Southwest Industr ial Park Specific Plan Storm Drain Master Plan and Appendices B and C for Existing Hydrology Exhibit and Proposed Hydrology Exhibit, respectively. Appendix A Southwest Industrial Park Specific Plan Storm Drain Master Plan Appendix B Existing Hydrology Exhibit Appendix C Proposed Hydrology Exhibit Appendix D Runoff Calculations G0 g3@/336)&F A’&F En:. .7MZ3- C ,C V#I *, C"61I6C.6NZ 66 6 ,6 666 66 Z6 RZ1.ZZW6 616ZS666666C1%QWof+G J 0. o / CZM F&) _#1@F&’q _# 5 . 6 3 - @,6 1&E Z M V666CS MZ)7 3M .6Z63 .6,36.66.6 6 ..6AC_’_M 31’)8 *.(F 3B+";+$3,B(%,(;3*& ,, -.--F ’F)F8F*F.F "*,(3B+0+*Y;*(- B(*B;+9B,(3+$,(0$ BB B9*aJJJJJJJ 9+BN*3 B$3,B(aJJJJJJJJJ -*$+ ,(* = < $$22$4 $ <1;9+!2@72@* 3))).*B5_a B]QV$&Z a " Y Y WUd’L" _ K 1= ’[H .T @ g [ 1 J U2 J 1+7 B JP F- .+7 $W 1 \\-B$B PX &.H S e BN #F@5 2 ,*[ -H*)C5_-V _#J &q,’&@ C .+ V Z C # B B+, B1B’(=1+#B ,(0,3+$3,B(+$3*0B+9*+?,B;$+*$%0&,!Q ,(0,3+$3,B(+$3*0B+ 9*+?,B;$+*$?*+; ;+?*(;*+2$4 $ 0 <@(’ +- 3))).*B5_a B]QV$&Z a " Y Y WUd’L" _ K 1= ’[H .T @ g [ 1 J U2 J 1+7 B JP F- .+7 $W 1 \\-B$B PX &.H S e BN #F@5 2 ,*[ -H*)C5_-V _#J &q,’&@ C .+ V Z C # B B+, B1B’(=1+#B ,(0,3+$3,B(+$3*0B+9*+?,B;$+*$%0&,!Q ,(0,3+$3,B(+$3*0B+ 9*+?,B;$+*$?*+; ;+?*(;*+2$4 $ 0 <@(’ +- Appendix E FEMA Flood Insurance Rate Map Appendix F Construction Documents