Water budgets are of particular interest in the Los Angeles water/energy system. Despite large water imports, much rainfall currently goes to waste as surface runoff through extensive flood control infrastructure. Due in part to reduced run-off, local groundwater aquifers are millions of acre-feet short of capacity. The City of Los Angeles has responded with integrated resource planning, committing to major investments in groundwater recharge projects and water recycling. There is also extensive interest in distributed, “green infrastructure” like rainwater harvesting, graywater systems, and bioswales. The revitalization of the Los Angeles River is a landmark project in the planning stages that is likely to pull together many of these green infrastructure elements.
The proposed research project seeks to model interdependence in the water/energy footprint for the City of Los Angeles, specifically the Los Angeles Department of Water and Power (LADWP). The modeling effort will report on water, power and air pollution (conventional pollutants and GHG’s) for technologies in the 2008 baseline water/energy system. The model will use life cycle assessment (LCA) to quantify energy intensity at all stages of the water supply chain for each type of water source: source and conveyance, treatment, distribution, end use, and wastewater treatment. By 2 water source, we include following: 1) Owens Valley via Los Angeles Aqueduct; 2) Sacramento Delta via California Aqueduct; 3) Local Groundwater; and 4) Recycled Water. We will also include energy intensity of selected promising conservation measures, such as rainwater capture and purifying recycled water. It will build on a 2006 study by the City of Los Angeles that integrated water supply, wastewater, and watershed management, but did not include energy use. This research, through the development of the water-energy footprint for Los Angeles, will provide a toolkit for water agencies to improve long-term integrated resource plans, which often grapple unsuccessfully to fully integrate the water/energy footprint in long-term planning.