ENERGY SAVINGS AND AIR QUALITY BENEFITS FROM THE SANTA CLARA VALLEY WATER DISTRICT'S WATER USE EFFICIENCY PROGRAMS

The Santa Clara Valley Water District (District), the primary water agency for Santa Clara County, which encompasses the southern part of the San Francisco Bay, provides water supplies for an expanding urban population containing 1.8 million resident, hosting 200,000 commuters, and harboring Silicon Valley, a major economic driver for California.To help meet increasing water demands, the District has developed a comprehensive suite of water conservation and water recycling programs that have resulted in cumulative savings of 427,000 acre-feet (AF) of new water supplies between fiscal year (FY) 92–93 and FY 06–07. In addition to saving water, water conservation and water recycling programs save energy and reduce air pollutant emissions due to the significant quantities of energy required (and air pollutants generated by energy production) for the water supply chain: 1) Water conveyance; 2) Water treatment; 3) Distribution; 4) End use; and 5) Wastewater treatment.Air pollutants generated include (depending on energy source) the following: reactive organic gases, sulfur oxides, nitrogen oxides, particulate matter, and carbon dioxide. The latter is a greenhouse gas that contributes to global warming.The climate changes and other impacts that occur as a result of global warming present challenges for water agencies. Sea level rise (including saltwater intrusion into the freshwater San Francisco Bay-San Joaquin Delta levee system), a decrease in snow pack in the Sierra Nevada mountain range (which supplies water for much of the state), and increased drought are all possible outcomes of global climate change. The District is committed to responding to these challenges through adaptation (preparing for future changes) and mitigation (reducing the District's role in global warming through more efficient use of resources).With regard to the mitigation of global climate change, the District recently completed an analysis of the energy saved by its water conservation and water recycling programs, which have been in operation since FY 92–93. For FY 92–93 through FY 06–07, the District has saved approximately 1.62 billion kilowatt-hours (kWh) of energy, which represents a financial savings of approximately 208 million and is equivalent to the annual electricity required for 236,000 households. Through saving energy, the emissions of approximately 381 million kg of carbon dioxide, a greenhouse gas, were eliminated, which is the equivalent of removing 82,000 passenger cars from the roads for one year.