San Diego Water Plans for the Future, Turns to Desalination
As the rhetoric increases over the proposed Imperial Irrigation District water transfer to San Diego, the San Diego County Water Authority has unveiled a multibillion-dollar capital improvements plan that heavily relies on desalination.
In the latest battle over the transfer, the Department of the Interior warns that because it has been sued by the Imperial Irrigation District, it can now exercise the right of revisiting the entire agreement that was to have brought the water here.
"Accordingly, in light of these changed circumstances, the parties should not assume that earlier drafts of relevant documents, including the provisions regarding reasonable and beneficial use, will be acceptable to the United States," wrote Bennett Raley, assistant Interior secretary for Water and Science.
The IID sued Interior when the department withheld 200,000 acre-feet of water following the failure of the transfer to meet the Dec. 31 deadline. The valley could lose as much 500,000 acre-feet more under legislation now being kicked around Sacramento. Wherever that water ends up, the San Diego region is facing short supplies.
It is against this backdrop of increasing uncertainty that the SWCWA has presented its capital improvements program.
At the heart of this plan is a desalination plant being designed next to the Encina power plant a plant that would be expandable as needed. It would give San Diego access to the largest reservoir in the world the Pacific Ocean.
The initial plant would produce 56,000 acre-feet per year, or about 10 percent of the total demand here. An acre-foot is roughly enough water to supply two families of four for a year. The initial 50-million-gallon-per-day plant could be up and running in 2007 or 2008.
Earlier this month, a 25-million-gallon-per-day desalination plant opened in Tampa Bay. That plant was developed by Poseidon Resources of Stamford, Conn., which plans to build the Carlsbad facilities as well.
The plan would not be cheap. Desalination remains a very expensive technology, but pledged subsidies from the Metropolitan Water District would make the water more affordable than the $800 per acre-foot projected at present.
Water costs vary by district, but about $700 per acre-foot for agricultural water in the Valley Center area is about as expensive as it gets here. The subsidies would bring the cost into that range, perhaps as low as $650, SDCWA officials say.
"We're coming really close now (with desalination) to being competitive," said Dana Friehauf, SDCWA senior resources specialist.
Friehauf said the cost becomes even more competitive when considering that the higher cost water would be blended with a less expensive supply.
Along with the expense for the plant and any expansions that would follow, the desalination plan will need extensive piping systems that would go to Carlsbad and Vista first, before being distributed throughout the SDCWA's service area. Most of that area is in the western half of the county.
Pyle said discussions will be conducted over the next few weeks to determine the most suitable alignments for the pipelines from the plant.
The SDCWA has also been exploring how a desalination plant might work at the South Bay Power Plant in Chula Vista, but the Encina project is much further along.