Date of Graduation

Spring 5-18-2023

Document Access

Project/Capstone - Global access

Degree Name

Master of Science in Environmental Management (MSEM)


Environmental Management

First Advisor

Aviva Rossi


Southern California has access to a finite amount of water that is vulnerable to the state’s changing climate and growing population. The increasing population’s water demands and hydrologic variability due to climate change inspire different proposals to solve these water limitations. Seawater or brackish water desalination and wastewater recycling are all water resources that have the potential to help meet the water needs of Southern California, specifically the South Coast Hydrologic Region. Every water resource requires energy to transport, treat, and distribute the water for use; in an era of climate change, when energy use contributes to greenhouse gases, utilities need to consider the most sustainable option for providing water resources at the lowest use of energy. Southern California imports approximately a quarter of its water from the San Francisco Bay Area Delta. This energy intensive process is supported by the hydropower generated throughout the projects conveyance system. Desalinating seawater into potable water, using the method of reverse osmosis, requires large amounts of energy compared to other water resources. Despite this, private companies are still proposing to construct desalination facilities on the coast of California. All new seawater reverse osmosis facility proposals have been rejected except one remaining proposal for a facility in Orange County. Researchers continue to investigate ways to reduce the energy consumption for a seawater reverse osmosis facility but results claim there is little room left for further energy reductions. Other water resources such as wastewater recycling and brackish water reverse osmosis are providing water to the region with lower energy intensity requirements. This study compares the energy intensities between importing water and desalinating ocean water for the South Coast Hydrologic Region. Energy intensities for wastewater and brackish water treatment are also compared against importing water and desalinating sea water. It was found that seawater desalination continues to consume more energy compared to importing water from the State Water Project. It was also found that wastewater recycling and brackish water desalination had the lowest energy intensities compared against importing water and desalinating seawater. It is recommended to find ways for replacing the electricity, sourced by fossil fuels, to supply the Southern California with water resources. It is also recommended to replace a significant portion of water from the State Water Project, that has a considerably large energy intensity for transporting water, with local wastewater recycling and advanced wastewater treatment systems. In the future, all of these water resources have the potential to lower their total energy footprint and convert their electrical supply to a renewable energy source. The analysis on different energy intensities for water resources recommends an establishment of modernized wastewater treatment facilities to support the future water demands of the South Coast Hydrologic Region and ways to lower water resources’ energy intensities.