San Diego's Multi-Million Dollar Treatment Plants Stand Idle

San Diego has built out massive water infrastructure systems over the years that are now standing idle as water demand drops.

“This winter, demand for water was so low that the San Diego County Water Authority temporarily idled a $160 million plant in San Marcos that it built less than a decade ago. Water agencies that went into debt building treatment plants still have to pay up, whether the plant is needed every day or not,” Voice of San Diego recently reported.

Officials are debating how to pay for the facilities that remain, the report said.

“Some of the [county’s] plants are still being paid off because agencies went into debt to build them. That means even as water use goes down, water rates for some customers will go up.”

Water demand is significantly below the capacity of the county’s plants.

“In San Diego County alone, a dozen major treatment plants can produce up to 830 million gallons of drinking water each day. Yet even when demand for water was highest — the dry summer months, usually — the county’s plants last year were treating only about 530 million gallons per day of water,” the report said.

The county invested heavily in building out the capacity at its major facilities. In 2001, for instance, the Robert A. Skinner Filtration Plant in Riverside County was sometimes operating above capacity.

“By July 2007, Metropolitan had added 110 million gallons of treatment capacity to Skinner, allowing it to treat 630 million gallons of water per day — roughly as much as everyone in San Diego now uses in a day. That cost about $153 million,” the report said.

“The Water Authority’s Twin Oaks Valley Water Treatment Plant in San Marcos opened less than a year later, in April 2008. The plant can treat 100 million gallons of water per day. It cost about $160 million to build,” the report continued.

But after the drought began, county residents began using less water. Now, as California enters its fifth year of drought, the region dumped a half-billion gallons of expensive, treated drinking water, Voices of San Diego previously reported.

San Diego also opened “the first large-scale desalination plant in the state and only the second in the nation” last year, KPCC reported.

Officials say San Diego is thinking long-term.

“For instance, we don’t build freeways to handle traffic on Sunday morning, we build them to accommodate rush-hour traffic,” Mike Lee, a spokesman for the Water Authority, told Voices of San Diego.

For more drought-related coverage visit Water Online’s Water Scarcity Solutions Center.