'Paleo channel' finding could mean more water from Dana Point desalination plant

The South Coast Water District may have room for a larger well system for its proposed desalination facility in Dana Point, meaning that more potable water could be produced for customers.

At a meeting last week, consultant Mark Donovan, a senior engineer with GHD, Inc., told South Coast's board that an ancient river channel topped with younger sediment — known as a paleo channel — at the mouth of San Juan Creek is larger than "orginally anticipated."


"These are positive preliminary findings," Donovan said. Geophysicists used sonar to map the area in October.

South Coast is proposing to drill slant wells at Doheny State Beach — drilling at an angle to draw water from under the ocean floor — as part of the Doheny Ocean Desalination Project.


Donovan said initial projections had nine wells around the creek's outfall. It was unclear whether the recent discovery would mean more wells or whether the nine would be expanded.

South Coast, which serves customers in South Laguna, Dana Point, San Juan Capistrano and San Clemente, is proposing a 5-acre facility on 30 acres of district-owned property near San Juan Creek that would produce 4 million to 5 million gallons of potable water per day, with the possibility of increasing the output to 15 million gallons per day.

The district imports 80% of its water from the Colorado River and Northern California. The remaining 20% comes from recycled and groundwater sources.

Desalination proponents hail the process as a method of providing a reliable water source during drought years or if an earthquake was to damage pipes that transport water.

The project could cost $85 million to $90 million in design and construction.

In a letter to South Coast last fall, Boston-based Poseidon Water said it would be interested in pursuing a public-private partnership on the Dana Point facility should South Coast choose that approach. Poseidon also has proposed a highly controversial desalination plant in Huntington Beach.

The district board will discuss pros and cons of a public-private partnership during a workshop, expected in May. A draft environmental impact report could be released this summer.

In the wake of a series of forceful storms, South Coast board member Rick Erkeneff urged the district to consider pitfalls of the location.

"There is quite a bit of beach erosion down there," Erkeneff said. "It doesn't matter what side you are on. The scenarios for sea-level rise, this area is going to be vulnerable."

Twitter: @AldertonBryce