South Orange County, CA
PACE provided design services for the 26-acre Gobernadora Multi-Purpose Stormwater Treatment and Storage Project that recycles urban dry weather and stormwater, provides greening and recreational opportunities and provides regional flood control benefits. This basin provides several benefits including treatment and recycling of captured runoff and storm flows, reduction of downstream erosion and sedimentation, detention of peak storm flows, and water quality improvement to Gobernadora Creek. The system is successful due to its dynamic hydraulic operating system incorporating automated controls that can respond to both low flow and high storm flow conditions in the creek. Operational flexibility is facilitated through multiple hydraulic systems including a dry weather nuisance runoff diversion structure featuring a rubber inflatable dam system to divert flows into natural water quality treatment and infiltration cells, an elevated side weir to capture storm flows for peak flow storage, a secondary rubber dam for large flood flow water level control, sedimentation basin and fine straining, disinfection, and a pump station to transport treated flows for recycled water applications. The system accommodates a projected 350 to 800 AF of dry weather flow recovery and provides storm flow detention up to the 100-year storm event.