Since adoption of their WMPs, the Lower LA River (LLAR), Lower San Gabriel River (LSGR), and Los Cerritos Channel Watershed Groups (Gateway Watershed Groups) have made significant progress designing and constructing impactful, multi-benefit stormwater capture infrastructure throughout the region (at least 20 regional projects completed, in construction, being designed, or analyzed for feasibility—totaling over $100M of funding secured for new infrastructure); however, as more projects successfully come online, the Groups identified the need to better understand how the overall system of projects functions at the watershed scale so that they can efficiently prioritize projects for Safe, Clean Water Program support. While WMPs provided a flexible, watershed- and sub watershed-scale “recipe for compliance,” the longer-term plan is coarse, leaving the Groups in need of implementation-scale details to plot out their project-by-project pathway to clean water (e.g., what additional projects are possible throughout the watersheds, which are the most strategic projects to pursue collaboratively, and in what order should they be designed and built?). Answering these questions will enable the Gateway Watershed Groups to make more informed decisions about which projects to fund with taxpayer dollars through the Safe, Clean Water Program, support continue adaptive management of their WMPs, and help them respond to concerns from the State Water Resources Control Board regarding WMP specificity.
The first phase of this study developed the methods and test the GAP approach in a portion of each Watershed Area to demonstrate regional value over a short-term planning horizon. Phase 2 scales the approach region-wide and over a longer-term planning horizon in collaboration with the Watershed Coordinators and Gateway Watershed Groups, including targeted field visits to validate site-specific engineering feasibility assumptions. Outcomes will support the Gateway Watershed Groups as they adapt their WMPs over time and will provide the LLAR and LSGR WASCs with supplemental, objective information for consideration when programming future Stormwater Investment Plans.
This study was funded in full from the Los Angeles County Flood Control District’s Safe Clean Water Program.
Click here to access the Gateway Area Pathfinding Phase 2 Stormwater Considerations Memo