PC-2025-09 - Laserfiche WebLink

P23-0480 and TR8680 Planning Commission April 23, 2025 Page 17 of 31 give notice to the City Engineer when final monuments have been set and when payment for said work has been received from the subdivider. (Address this condition prior to final map approval) 76. STORMWATER HYDRAULICS: The City’s storm drainage network has been designed in accordance with the Alameda County Hydrology and Hydraulics Manual published by the Alameda County Flood Control & Water Conservation District. Said manual is available for download at: https://acfloodcontrol.org/the-work-we-do/the-work-we-do-hydrology-manual/ The City is located in Zone 7, and its storm drain pipe network is considered a secondary facility. Any connections to, additions, or upgrades to the City’s pipe network shall be designed in accordance with the manual. Calculations submitted for review/approval shall be presented in a format consistent with the “Calculation Form – District Rational Method” available in the manual. The calculations shall demonstrate adequate freeboard given the design storm event, assuming all bioretention areas are overflowing. Said calculations shall be prepared, stamped, and signed by a California-licensed civil engineer. (Address this condition prior to improvement plan approval) 77. BAHM REPORT INCONSISTENCY: The Bay Area Hydraulic Model (BAHM) shall be consistent with the relevant Stormwater Management Plan(s) and the Project’s final design. (Address this condition prior to improvement plan approval) 78. STORM WATER PUMPS: Referring to the vesting tentative map, the storm drain design relies on pumps to lift water that collects in the sump and pipe network for treatment within the bioretention areas. A system or weirs, orifices, valves, or switches shall be designed to direct only water from the 2-year storm to the pump system for treatment in the associated bioretention area. All stormwater from events larger than the 2-year storm shall bypass the pump system and go directly to the downstream conveyance network. The pump system shall therefore only convey water from 2-year and smaller storm events. After the storm event passes, the pumps shall fully evacuate all water from the sump to prevent vector propagation. All pump systems installed within the storm drain network shall have controls that integrate with the City’s supervisory control and data acquisition (SCADA) system for remote monitoring. (Address this condition prior to improvement plan approval) 79. EMERGENCY OVERLAND STORMWATER FLOW/SUMP PROPERTIES: All properties within the Project site shall be designed with an emergency overland flow path to direct storm runoff to the nearest public street or open flood control facility in the event on -site pipes become plugged, as shown on the Project Plans (including the VTM). The flow path shall be lower than the finish floor elevation of all habitable structures. The flow path cannot rely on neighboring properties unless a storm drain easement across the neighbor is obtained. Sump properties shall be designed to discharge the 50-year recurrence interval storm event through the pipe network before habitable structures become inundated. (Address this condition prior to improvement plan approval) 80. SANITARY SEWER DESIGN STANDARDS: Connections to the City’s sanitary sewer network shall conform to Pleasanton Municipal Code Title 15 “Sewerage”. All buildings Docusign Envelope ID: 2B93F64A-C49E-4C2A-BF54-785F6FDA6546