A proposed desalination facility producing 5 million gallons of drinkable water a day would satisfy the needs of all South Coast Water District customers, district General Manager Andy Brunhart said this week, though he added the agency would not rely completely on that source to serve ratepayers.
The 5-acre Doheny Ocean Desalination Project would be built on 30 acres of district-owned property near San Juan Creek in Dana Point.
"We would never want to be 100% desalinated water," Brunhart said Thursday. "We always want to take some [imported] water so pumps do not rust and decay."
He added that if other cities are decimated by an earthquake, South Coast could transport water through pipelines to its neighbors.
South Coast serves 35,000 residents and 1,000 businesses in South Laguna, Dana Point, San Juan Capistrano and San Clemente.
The district will hold the next in a series of workshops about the Doheny project on Wednesday. Brunhart plans to seek the board's direction on a preferred ownership structure for the plant.
Two options are a district-owned facility or a public-private partnership.
In the latter scenario, a private company would design, build, finance and operate a facility while the district would pay for water once it was delivered.
Desalination has been a topic of interest for several years but has been the subject of debate in Orange County recently with concerns about water supply during drought conditions.
In Huntington Beach, Poseidon Water is proposing a facility that would generate 50 million gallons of drinkable water per day. Many residents there oppose the project on environmental grounds.
South Coast imports 80% of its water from Northern California and the Colorado River at the rate of $1,075 per acre foot, according to district statistics.
With an annual need of 5,100 acre feet of water to serve its customers, it costs the district $5.4 million to purchase water from the Municipal Water District of Orange County, a wholesale supplier, according to South Coast.
An acre foot is equal to 326,000 gallons, or enough water to cover an acre of land 1 foot deep.
Municipal Water purchases imported water from the Metropolitan Water District of Southern California.
The projected cost of imported water in 2020 is $1,240 per acre foot, according to the district.
With an anticipated need of 5,460 acre feet per year, the district's annual cost to buy water would be $6.7 million.
Brunhart said there are plans to develop more condominiums and hotels in South Coast's coverage area and therefore an anticipated increase in water needs.
It would cost South Coast more — $1,465 per acre foot — to produce potable water from a district-owned facility that generates 5 million gallons of water per day than from imports, the district said.
The cost would jump to $2,170 per acre foot under a partnership with a private company, Brunhart said.
With a projected need of 5,460 acre feet per year in 2020, it would cost South Coast $8 million annually with a district-owned plant compared with $11.8 million under a partnership.
Water costs more under a public-private partnership because a private entity seeks a profit, Brunhart said. That said, the district acknowledged that it would assume greater risk for designing and building its own plant during a presentation to the board Oct. 31.
The earliest a facility could be operational is December 2020, Brunhart said. A draft environmental impact report on the project could be completed by June.
The district also has given projections for a facility that produces 15 million gallons a day.
The reason the district is considering a facility that could produce 15 million gallons per day is that it could potentially sell some of the water to other agencies.
"Our desire is to have the ocean desalination facility at Doheny be a regional resource, more than just the district, because it's the right thing to do for Orange County," Brunhart said.
Under the proposal, crews would drill wells extending from Doheny State Beach to draw water from under the ocean floor rather than from open water.
The average person in South Coast's coverage area uses 90 gallons of water per day, according to district statistics.
Poseidon Water approached South Coast last year about a potential partnership.
Brunhart said representatives from other companies have attended prior meetings and workshops on the proposed Doheny project.
Wednesday's meeting begins at 3 p.m. at South Coast's office at 31592 West St., Laguna Beach.