CWE assisted with design coordination of the storm drain and water quality elements; provided hydrology, hydraulics, and water quality calculations; prepared stormwater reports; and provided construction support services as part of Los Angeles County Department of Parks and Recreation’s (LACDPR’s) Park to Playa Trail Bridge project’s Phase 1B Design Development. The 13-mile trail connects the Baldwin Hills Parklands to the Pacific Ocean via the Stocker Corridor, Kenneth Hahn State Recreation Area, Stoneview Nature Center, the Baldwin Hills Scenic Overlook, and Ballona Creek Bike Path. It represents the first regional trail in South Los Angeles and the entire Second Supervisorial District of the County of Los Angeles, and includes a wildlife corridor for animals to cross La Cienega Boulevard. The bridge was drained with longitudinal edge drains on either side of the crowned concrete deck, and all drainage from the bridge is routed through a vegetated swale. The site design met LID requirements to increase groundwater recharge, enhance water quality, and prevent degradation to the downstream natural drainage course. Preliminary hydrology and hydraulics drainage reports were prepared to address stormwater quality to meet Municipal Separate Storm Sewer System (MS4) and National Pollutant Discharge Elimination System (NPDES) Permit requirements. A preliminary hydrology report was prepared using Advanced Engineering Software (AES), Water Surface Pressure Gradient (WSPG), and Federal Highway Administration Visual Urban (HY-22) software. Tasks included coordinating and conducting two stakeholder workshops to gain consensus on the design development and discuss constraints, design, and construction issues the project posed; investigated/evaluated existing site conditions and elements, including existing landscape, grading and drainage conditions, irrigation equipment, and utilities; review topography, utility easement and right-of-ways; and reviewed existing drainage reports for the Stoneview Nature Center and the portion of the Inglewood Oil Field; providing Plans, Specifications, and Estimates (PS&Es) including a Basis of Design Report (BDR), using GreenBook and CSI standards; and submitting applications and permit fees with third parties such as the City of Los Angeles, City of Culver City, Regional Water Quality Control Board (RWQCB), and LACPW Divisions.