Poseidon desalination plant scores low in ranking of Orange County water projects

The controversial Poseidon desalination plant proposed for Huntington Beach is the least cost-effective option and carries the most fiscal risk of key water projects being pursued in Orange County, according to a newly released draft report.

Additionally, the plant would produce far more water than needed except in the most extreme scenarios and most shortages could be met by other projects, according to the report by Municipal Water District of Orange County, which oversees water imported into the county.

A final version of the report, which analyzes the county’s future water needs and projects underway to meet those needs, is expected by the end of the year.

The Orange County Water District, which manages local groundwater distributed to north and central Orange County, has criticized the draft findings as incomplete.

OCWD’s board voted 6-2 in July to sign a preliminary agreement with Poseidon for the $1 billion-dollar plant. Poseidon needs two more regulatory permits, including one from the Coastal Commission, before OCWD will consider finalizing a contract.

“I think we’ve done a pretty good job of managing the groundwater basin without anybody telling us what to do,” said OCWD board member Cathy Green, a supporter of the Poseidon project.

OCWD has been widely lauded for its innovative water recycling program, in which it pumps purified sewage water into the groundwater to bolster local supplies.

The study says its intent is to provide the county’s numerous local water agencies with information to help with planning decisions.

“We’re not telling agencies what they should do,” said MWDOC General Manager Robert Hunter. “We’re providing an analysis.”

Future water sources

MWDOC’s study examines the future of water supplies imported to Orange County as well the increased likelihood of extreme droughts and rains as predicted by the latest climate change projections.

But the report focuses most sharply on Orange County itself, starting with the differing need for imported water by region:

• La Habra and Brea have the least need for imported water, with 90 percent produced locally.
• North and central Orange County, most of which have local agencies served by both OCWD and MWDOC, gets 75 percent of its water locally.
• South Orange County gets just 5 percent to 10 percent of its water locally.

Because south county is most dependent on imported water, it’s considered most vulnerable to shortages caused by drought or because of emergencies, such as earthquakes which could damage the pipelines and aqueducts carrying water from northern California and the Colorado River.

Imported water costs more than that from local sources, which also increases the desirability of more water options for South County.

The study targeted five key Orange County water project proposals, three of which were divided into two parts for ranking purposes. Poseidon, which has been in the works for two decades, has long attracted the most public attention.

The projects, ranked from most cost effective to least:

• Doheny desalination plant. This project being pursued by the South Coast Water District would be less than a third of the size of the Poseidon plant and uses technology that environmentalists prefer to Poseidon’s. It would initially provide 5,000-acre feet for the water district, with the ability to expand to 15,000 if other south county districts want to participate. The broader proposal ranked first and the SCWD portion alone tied for fourth among the eight proposals.
• Cadiz Water Bank. The Santa Margarita Water District is pursuing a plan to capture 5,000-acre feet a year from this project in San Bernardino County’s Fenner Valley. SMWD’s plan ranked second, while the possibility of importing another 5,000-acre feet a year from the bank to other agencies ranked sixth.
• Strand Ranch Water Bank. The Irvine Ranch Water District has purchased facilities in Kern County to tap into this water bank, which could provide the district as much as 17,500-acre feet during emergencies or when other imported water supplies are reduced because of drought. It ranked third.
• San Juan Watershed Project. SMWD is the lead agency for this project, which could increase south county groundwater supplies by 9,500-acre feet a year. It would trap ocean-bound stormwater and and also use recycled water to recharge.s This tied for fourth.
• Poseidon desalination plant. This OCWD project would produce 56,000-acre feet a year, with as much as 16,000-acre feet going to south county and the rest going to north and central Orange County. The south county portion of the project ranked seventh while the north and central county portion ranked eighth.

The county’s total annual need is expected to be about 600,000-acre feet through 2040, with increases due to population growth offset by decreases resulting from conservation.

Push back

The main downsides of Poseidon is the cost and the question of whether the water will be needed.

If imported water flows continue without reduction, the Poseidon project could cost customers nearly $250 million more than if they simply continued relying on imported water to supplement local supplies, according to the report.

However, it also notes that the project could be beneficial if climate change proves greater than the most extreme predictions used in the study or if OCWD wants greater independence from imported water.

MWDOC’s study predicts shortfalls for OCWD customers could range from none to 22,000-acre feet annually — far less than Poseidon plans on producing. The study lists 10 smaller potential OCWD projects that could collectively more than cover the maximum projected shortfall, although there is no cost analysis.

“(OCWD) asked us not to analyze these projects — that it was their business, not ours, ” Hunter said. He added that his district worked with all water providers in the county in preparing its analysis.

Poseidon Vice President Scott Maloni declined comment, saying he was still studying the report. But an OCWD letter to Hunter says that there was inadequate interaction with others and too many assumptions were made.

Some Poseidon supporters believe the plant’s water will eventually cost less than imported water.

“Having the MWDOC Study in effect telling your member agencies how they should spend their money is not appropriate,” says the letter from OCWD General Manager Michael Markus.