The project involves the comprehensive design and engineering of a private on-site stormwater drainage system for a development located in Los Angeles. The scope includes a detailed hydrologic analysis to manage peak flow rates, ensuring the site effectively handles a 50-year design storm frequency with a modeled rainfall depth of 7.03 inches.

To manage runoff where gravity drainage is not feasible, the design features a sophisticated duplex submersible sump pump system. This system is engineered with a 1,250-gallon sump basin and two high-capacity pumps, each rated for 200 GPM at 40 feet of Total Dynamic Head (TDH). The layout integrates various area drains and cleanouts connected via 4-inch Schedule 40 PVC piping to ensure maintenance accessibility and structural protection.

All engineering specifications comply with the 2022 California Plumbing, Building, and Residential Codes, as well as specific Los Angeles Plumbing Code (LAPC) amendments. The final discharge is designed to be conveyed to an approved point of disposal, such as a gravity drainage system or city storm drain, maintaining strict adherence to local municipal requirements.