Metropolitan's Water Planning and Stewardship Committee discusses desalination in Southern California

The Metropolitan Water District’s Water Planning and Stewardship Committee received an update on desalination facilities currently being planned or considered for the Southern California area at their meeting on September 10, 2012. I listened in via webcast.


Warren Teitz, Senior Resource Specialist at Metropolitan, began by detailing the history of Met’s desalination subsidy. In 2005, the Metropolitan board approved agreements with five agencies for subsidies of $250 per acre-foot. The five agencies were West Basin, Metropolitan Water District of Orange County (MWDOC) , Long Beach Water Department, LA DWP, and the San Diego County Water Authority. Metropolitan currently has signed agreements with three of them: West Basin, MWDOC, and Long Beach. Staff notes that $250 acre-foot is on par with the subsidies Met offers for recycled water projects and groundwater desal projects. The desal subsidy contracts extend 25 years or until 2040, whichever comes first. Contracts do include certain milestones, most notably a requirement that the project must be up and running by 2020, otherwise the contract is automatically terminated. Also, the project’s final documents and EIR must be submitted to the Metropolitan board for approval.

Mr. Teitz then briefly updated the committee on the basics of desalination. Power is a significant expense, so how do the energy requirements of desalination compare to SWP water? Not so different, says Metropolitan staff: “Most makers of seawater desalination membranes give you what their salt rejection is at 800 pounds per square inch. And to give you an idea of the amount of power that is, it is the same amount of power to lift water over the Tehachapi Mountains.” However, energy recovery devices can help reduce the amount of power used, and it is these devices that have helped to make desalination more cost-competitive, Mr. Teitz noted.

State Water Board is working on updating their ocean plan to include desalination facilities. They are looking at the impacts of intakes and high-salinity brine on aquatic organisms.

Currently there are four projects significantly underway in Southern California:

  • Long Beach Water Department: This is a 10,000 acre-foot per year project expected to be online in 2020. Pilot study and water quality tests have been completed, and they are now embarking on long-term tests of a subsurface intake called an infiltration gallery. It is essentially a filter bed at the bottom of the ocean floor designed for minimal impact to sea life. They are also testing the possibility of discharging brine through the same sort of device/technique. They will be doing further testing before moving forward. For more information on Long Beach Water Department’s Seawater Desalination Program, click here.
  • Metropolitan Water District of Orange County (MWDOC) – South Orange Coastal Ocean Desalination Project : Also known as the Dana Point project, this is a 16,000 acre-foot project that would potentially be online by 2018. They are testing slant-well intakes, as well as studying the intakes to see if how it might impact the upstream aquifer. They are also doing iron and manganese studies. For more information on the South Orange Coastal Ocean Desalination Project, click here.
  • West Basin Municipal Water District: This 20,000 acre-foot project is planned to be online by 2017. They have completed their pilot studies and are now operating much larger demonstration study. The master plan study is nearly complete and they are getting ready to issue an RFP for the preliminary environmental work. West Basin is looking at two potential sites, one in El Segundo and the other in Redondo Beach. For more on West Basin’s ocean desalination program, click here.
  • San Diego County water Authority: The Poseidon Carlsbad plant plans to produce 56,000 acre-foot per year. Permitting for this plant is complete, and San Diego County Water Authority and Poseidon are currently negotiating the water purchase agreement. The water will be integrated into San Diego’s regional distribution system. The projected online date is 2016. For more on San Diego County Water Authority’s ocean desalination projects, click here.

Other regional desal projects in the planning stages:

  • Poseidon – Huntington Beach: MWDOC is the lead agency with other local agencies and retail agencies also involved.. This plant would produce 56,000 acre-feet per year and would be potentially online by 2017. This plant is currently in the permitting stage and due to go to Coastal Commission in the upcoming months.
  • Camp Pendleton: A San Diego County Water Authority project. This project would begin at 56,000 acre-feet per year up and be phased-in up to 168,000 acre-feet per year. This project is currently In the planning stages with a time frame for completion sometime after 2020.
  • Rosarito Beach: Two projects could potentially supply water to Southern California. Both are in pre-planning stages and have post 2020 time frames:
  1. Consortium of Metropolitan, San Diego County Water Authority, and entities in Nevada, Arizona and Mexico are looking at a plant in Rosarito to augment Colorado River supplies. A feasibility study was completed in 2010. Mexican partners are now working on pipeline alignments. This project could supply water to Metropolitan service area either by direct deliveries or through some sort of exchange with Mexico for Colorado River supplies.
  2. Otay Water District is working on a project at same site with a private developer; this project would be phased in and could produce 22,000 afy to 56,000 afy.


Director Wilson asked Mr. Teitz about a listing of incentives that Metropolitan has committed to. How much in total projected costs for Metropolitan over the life of these projects?, he asked. Staff answered that at $250 per acre-foot, when Metropolitan signed the agreements, if all five agencies had come online and all five agencies produced the water they said they would, it would be upwards to $350 million dollars. We have no further information until those projects move forward and we see what they are going to do, he said. Another director pointed out that San Diego’s subsidy needs to be subtracted from Metropolitan’s figure because currently San Diego won’t be receiving the subsidy due to litigation.

Director Brick: “There’s a critical issue that we seem to be avoiding, and that is, what is Metropolitan’s role with the development of desal? When we approved these agreements 10 or 12 years ago, it strikes me as strange that there weren’t performance measures included in there, because clearly it’s important if Metropolitan is going to be making commitments to support these projects in the future, there ought to be milestones … and here we are 10 or 12 years later still wondering what the progress of the various projects is and what Metropolitan’s role is going to be supporting those projects.” Some of these projects are large, complex, and have many issues in regards to financing, permitting, governance, and ownership of the resource, says Director Brick, and Metropolitan should be playing a leadership role.

In regards to San Diego, Director Brick continues: “One of our member agencies seems to be moving ahead and close to making a decision about its participation in a major desal program; I think we need to ask some questions too. When we established those contracts, it was with the intent of Metropolitan to be getting more out of them than just giving $250 an acre-foot … there was the intent that Metropolitan would get some sort of knowledge and advancements in the latest state in desal technology, as well as some expertise in how to develop projects like this, anticipating that Metropolitan might play a greater role in the development of desal. … However the kind of program that is being structured at the plant in Carlsbad, which is a simple water purchase agreement, doesn’t provide any of those benefits that were anticipated in these contracts. We haven’t really, as a board, grappled with that, or with Metropolitan’s bigger role. … I don’t think those agreements are appropriate anymore.

Another director present (sorry, didn’t catch the name) says certainly there must be water cheaper than desalinated water, and considering it’s on the wrong end of the system, he asks where the market’s going to be for ocean desal? He doesn’t see it being used for anything other than stand by.


The presentation to the committee gives the production of the desal plants in acre-feet per year, a much more useful figure than gallons-per-day as I usually see it specified. So just how much is an acre-foot? It is about the amount it would take to cover a football field to the depth of 1 foot and it is generally considered to be the amount of water that two households of four occupants each would use in a year.

So, then, consider the output of these proposed facilities in terms of households they would support. The largest plant so far, Poseidon’s plant in Carlsbad, would provide 56,000 acre-feet per year, or enough to supply just 112,000 households. If all four of the desal plants currently under development are completed, they would serve only 204,000 households.

It wasn’t mentioned in this meeting, but I’ve heard it said at other meetings that Metropolitan staff had determined that if Met were to replace State Water Project water with desalinated water, it would take a desal plant every 4 miles stretching from San Diego to Ventura.  For a rough estimate of how many desal plants that would be, Google tells me it’s 163 miles to drive from San Diego to Ventura, so that would be 40 desal plants – and that would be just to replace a portion of Southern California’s water supply.

Another problem brought up at the end of this part of the meeting is that desalinated water is produced at the bottom of the delivery system. Met’s infrastructure to deliver water starts out at a large capacity as the water arrives in Southern California from the north and the east, and gets progressively smaller as the water is distributed throughout the service area and approaches the coast. Bill Hasencamp once described the process of taking in a large amount of desalinated water into Metropolitan’s infrastructure at the coast as akin to “trying to get a blood transfusion through your little toe.”

While desalinated water could possibly provide local solutions for coastal communities, clearly desalinated water is not going to be the silver bullet for Southern California’s water supply problems.

Click here for the webcast. The desalination update is item 7b.

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