Sustainable LA Grand Challenge

This report explores the potential to improve water quality standards while integrating complementary One Water Management practices that can increase potential local-water supplies for the City of Los Angeles (the City) in the highly urbanized Dominguez Channel (DC) and Machado Lake (ML) watersheds.  To assess the integrated water landscape in this watershed, the report also looks at current practices and future opportunities at the Terminal Island Water Reclamation Plant (TIWRP) and in the underlying adjudicated groundwater basins: West Coast Basin and Central Basin.  

Implementing watershed-scale best management practice programs to meet stormwater permit requirements will significantly improve water quality in these watersheds. However, additional mechanisms such as implementing the City’s Low Impact Development ordinance and comprehensive source tracking and source control mechanisms will be required to potentially eliminate water quality exceedances.   

TIWRP currently treats nearly 15 million gallons per day (MGD) of wastewater with advanced-water treatment for reuse; however, sufficient demand exists locally to utilize approximately 25 MGD.  West Coast and Central Basins provide multiple opportunities to increase our local water supply through increasing recharge and extraction in these basins, including 450,000 acre feet of available dewatered space in the basins.  This research demonstrates the complex interrelationships between all aspects of urban water management, including, for example, stormwater management and local water supply.