Environmental activist Marco Gonzalez was irked to see the San Diego County Taxpayers Association recently give a Golden Watchdog award to the Carlsbad Desalination Plant . Besides arguing that the region should simply use less water, he argues that desalinated seawater is more expensive than imported water from the San Joaquin Delta and the Colorado River.
It’s surprising to see an environmentalist prefer imported water over desalinated seawater. Extracting water from the Delta and Colorado River has negative impact on fish and birds, and some of that water is lost on its way to San Diego County through evaporation and seepage.
In 2004, Poseidon estimated a $250 million cost to build the plant. When it opened in December 2015, the final construction cost was $1 billion.
Some of that quadrupling of expense resulted from years of delays caused by environmental groups trying to stop the project with lawsuits and other tactics. Construction unions also took advantage of environmental laws and required Poseidon to hire union labor.
Gonzalez compares the cost of desalinated seawater to imported water, which today comprises 75 to 80 percent of the water supply in the San Diego region (down from 90 percent before the Carlsbad Desalination Plant opened). But the desalination plant is part of a larger deliberate plan to reduce dependence on a long-distance water supply system vulnerable to disruption from earthquakes, sabotage, drought or disputes over water rights .
San Diego County water customers would regard desalinated seawater as a bargain if supplies from the San Joaquin Delta or Colorado River were abruptly cut. They would be praising Poseidon Water and the San Diego County Water Authority for wise planning in diversifying water supply sources.
While criticizing the desalination plant, Gonzalez promotes Pure Water San Diego , a project to recycle wastewater that is otherwise dumped in the Pacific from the Point Loma Wastewater Treatment Plant.
This project may be a nice example of recycling, but it’s no deal for ratepayers. A San Diego Public Utilities Department concept paper  recently submitted to the California Water Commission estimates that Pure Water San Diego will cost $3.2 billion to produce 93,000 acre feet of water per year by 2035. That’s $34,409 per acre foot.
Compare that rate with the already operational Carlsbad Desalination Plant, which cost $1 billion and is expected to produce 56,000 acre feet of water per year. That’s $17,857 per acre foot.
There is another factor in water projects that drives costs higher: electricity. Seawater desalination requires more electricity than pumping the same amount of water from the San Joaquin Delta and over the Tehachapi Mountains. And in California, environmental policies are inevitably raising the costs of electricity.
Poseidon Water is trying to reduce that electricity requirement for seawater desalination. In fact, San Diego Gas & Electric recently named Poseidon Water as an “energy champion” for 2016. The award recognizes devices at the desalination plant that save 146 million kWh per year. According to SDG&E, the Carlsbad plant is already operating at 11 percent below the energy consumption guarantees in its agreement with the San Diego County Water Authority. But even as Poseidon reduces the plant’s energy consumption, environmentalists are continually pushing for additional costly state and regional mandates that will ultimately negate any ratepayer savings.
Critics of the more expensive water are a major reason why the water is more expensive. In the end, what matters most for San Diego County ratepayers is that the Carlsbad Desalination Plant is now providing an ample uninterrupted supply of water from a local source. By reducing dependence on imported water, seawater desalination is creating better conditions for economic growth, for job creation and for quality of life.
Kevin Dayton is a research analyst with the California Policy Center. He is collaborating on a report about private investment in water infrastructure projects.