Chula Vista's Sweetwater Authority announced Wednesday its board of directors has approved an agreement with Poseidon Resources Corp. to purchase 2,400 acre-feet per year from its proposed Carlsbad desalination plant, scheduled for completion in 2009.

Connecticut-based Poseidon has already signed purchase agreements with the city of Carlsbad, and the water agencies of Valley Center and Rincon del Diablo. Nearly 70 percent of the plant’s 56,000 acre-feet-per-year, or 50 million-gallon-per-day, capacity is now subscribed through long-term water purchase agreements.

The proposed $270 million desalination project has received all of its local approvals and is currently in the process of applying to the California Coastal Commission for a Coastal Development Permit. Should the permit be granted, construction will begin at the Encina Power Station in Carlsbad, where the desalination plant will utilize the power plant's existing water-intake systems, now used for the plant's cooling.

Sweetwater currently receives 26 percent of its water supply from drought-resistant sources, such as wells and brackish groundwater desalination. Through this agreement, Sweetwater plans to acquire 10 percent of its future water supply from the Carlsbad plant, which would increase its drought-tolerant supplies to 36 percent by 2010.

“Seawater desalination is an important part of the solution to the region’s long-term water reliability needs,” said Sweetwater Authority board chairman and San Diego County Water Authority board member Bud Pocklington.

“The plant that Poseidon is building in partnership with the city of Carlsbad is capable of providing regional benefit to water agencies like Sweetwater," he said. "We stand strongly in support of advancing this critically needed new supply of high-quality water."