Case Study:
Water and Wastewater Utilities
Planning for Climate Change
The city of San Diego's Public Utilities Department provides both drinking water and recycled water services for its 1.3
million residents. Additionally, the city provides wastewater services to San Diego County's 2.2 million residents. 85
percent of the city's drinking water supply comes from sources - the Colorado River and the California State Water
project - that are far from the city, oversubscribed and highly vulnerable to drought, flood damage and system upsets.
The city of San Diego imports most of its water from the San Diego County Water Authority (SDCWA), the region's
water wholesaler. For the purposes of this assessment, the city chose to focus on the San Vicente Reservoir, one of
nine regional reservoirs that supply water to San Diego. All rain and runoff into San Vicente belongs to the city of San
Diego; however, due to dry weather conditions in recent years, minimal rain and runoff has been available. San Vicente
recently received a number of major capital improvements. These improvements included a project to raise the
reservoir's dam height to 117 feet as a part of SDCWA's Emergency Storage Project, in anticipation of the city's indirect
potable reuse program - known as the Pure Water San Diego Program - and other imported water intertie
opportunities. The Pure Water San Diego Program will help to reduce the city's dependence on imported water by
reusing locally available water supplies. Once the Pure Water San Diego Program is on-line, the city expects to
decrease its reliance on imported water from 85 percent to 60 percent.
Climate Threats
The city of San Diego is concerned with the impacts of climate change on their utility infrastructure and operations,
including the increased incidence of droughts, wildfires and coastal flooding due to rising sea level. Decreases in source
water quality due to changes in watershed characteristics after wildfires, such as increased erosion and sedimentation,
are also of concern.
Planning Process
To better understand the vulnerability of its utility infrastructure and operations, the city of San Diego assessed potential
climate change impacts using the U.S. Environmental Protection Agency's (EPA) Climate Resilience Evaluation and
Awareness Tool (CREAT). The CREAT assessment brought together individuals from EPA and various departments
within the city of San Diego to think critically about potential climate impacts, prioritize assets and consider possible
adaptation options.
Adaptation Measures
The city of San Diego considered the potential consequences of wildfires, drought and coastal storm surges to their
utility infrastructure and operations. To assess each of these potential threats, the city considered how potential
adaptive measures would help lower consequences. See the table below for potential adaptive measures that were
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Case Study: Water and Wastewater Utilities Planning for Climate Change
Fire Prevention
Monitoring Program
Enhanced fire management including increased level of brush management, controlled burns,
controlling invasive species, upkeep of habitable facilities and partnership with the California
Department of Forestry and Fire Protection (CALFIRE)
Infrastructure monitoring
Runoff monitoring to include a wet weather monitoring program in the San Dieguito
Watershed to characterize nutrient loads as they relate to wet weather events
Nutrient and contaminant modeling validated by the San Dieguito Watershed runoff
monitoring program
Agricultural and irrigation water demand models
Coastal Storm Surge
Groundwater monitoring
Sea-level rise and storm surge monitoring to address potential impacts to the Point Loma
wastewater treatment plant
Infrastructure monitoring to address potential impacts to the Point Loma wastewater
treatment plant
Effluent reuse through an Indirect Potable Reuse program, which will produce one third of the
city's potable water by 2035
Research community partnerships
Purchasing and importing water, bypassing the San Vicente Reservoir during water quality
events through a pipeline that is currently being constructed
Contact Information
For more information regarding the city of San Diego's climate adaptation planning, contact Goldy Herbon at
City of San Diego, California Case Study  Page 2
Office of Water (4608T)
EPA 800-Q-15-003
December 2015