Role of Metropolitan Water District

Role of the Metropolitan Water District of Southern California



To deliver water to the people living and working across Southern California, water supplies conserved at Cadiz must first be conveyed through a 43-mile pipeline to the Colorado River Aqueduct in Rice, California, then delivered via the CRA to water agencies and purveyors across the region. The CRA is owned by the Metropolitan Water District of Southern California (“MWD”) and extends 242 miles from Lake Havasu to Lake Matthews.


Before the Project can transport water in the CRA, MWD must make and approve conveyance, or wheeling, arrangements with the Project’s participating water agencies, including some of its own member retail agencies.


MWD’s review of such arrangements is governed by California law that requires the owner of a water conveyance facility to accept and convey water to complete a transfer in accordance with certain conditions if there is space available. (Water Code Section 1810 et. seq. “Wheeling Statute) In relevant part the Wheeling Statute provides:


“Notwithstanding any other provision of law, neither the state, nor any regional or local public agency may deny a bona fide transferor of water the use of a water conveyance facility which has unused capacity, for the period of time for which that capacity is available, if fair compensation is paid for that use…”


Cadiz and the Project participating agencies have not yet filed a formal application with MWD to secure wheeling arrangements.  The establishment of conditions for an arrangement will likely be influenced by a number of considerations concerning, timing and quality of the water that will be conveyed along with a consideration of any “offsetting benefits” including reduced treatment costs for total dissolved solids.


Project participants and Cadiz have committed that the transportation of Project supplies in the CRA will not harm MWD or its family of agencies in any way.  Cadiz water quality is regularly measured and satisfies every state and federal drinking water standard and could easily be treated to meet any required water quality standard pertinent to local groundwater.


The following areas are known to be primary considerations important to MWD staff regarding its conveyance of water for Cadiz Project participants –



Water Quality

Water quality at Cadiz is suitable for both domestic and agricultural use without treatment.  The vast watershed in which the water originates has very few overlying land uses and is free from the threat of bacterial waste and industrial contamination.


Total Dissolved Solids (TDS), a key measurement for determining water quality, typically ranges from 300 to 400 milligrams per liter (mg/L) at Cadiz, significantly lower than California’s Colorado River supply which can be as high as 800 mg/L in drier years. A recent report found that blending Cadiz water into the Colorado River Aqueduct that will save Southern California ratepayers nearly $400 million over the life of the Water Project.


Cadiz groundwater has also been tested for all metals and constituents regulated by State of California and the federal government. Cadiz Water quality, as described in the Cadiz Water Project’s Court-approved EIR, is below State & Fed MCLs, including Chromium-6 and Arsenic. But the Project is prepared to and will treat constituents to legal standards established by MWD to enter the CRA.


For the avoidance of doubt and in the event of future water quality regulations, in 2015, Cadiz partnered with ATEC Systems Associates Inc., a water treatment technology firm, to treat Project water supplies for Chromium-6 on site at the wellhead. Pilot testing results demonstrate that the ATEC technology can cost-effectively remove Chromium-6, Arsenic and other metals from Cadiz water if required by MWD as a condition to enter the CRA.


Finally, the Cadiz Water Project source of supply must be certified by the California Division of Drinking Water as in compliance with all drinking water standards before it will ever join with other regional and local waters for distribution to customers.  No water would ever reach a customer in Southern California that doesn’t meet these standards.




MWD will control access to the CRA and the schedule for moving Cadiz water. We believe the Project’s public water agency participants and MWD can come to agreement on a schedule that is mutually beneficial and meets the needs of the system.  The historical record of deliveries maintained by the United States Bureau of Reclamation reflects that physical space has been available annually within the design capacity of the CRA in every year since the Quantification Settlement Agreement (QSA) was adopted in 2002 (see table below).   Cadiz supplies would represent approximately 4% of aqueduct design capacity and only three inches in that conveyance system. Though designed to move 1.25 Million acre-feet (MAF), the system has moved up to 1.3 MAF annually in its history.   Extending an annual delivery schedule to accommodate this new reliable supply would not harm MWD.  Moreover, existing permits for the Project would enable the in-lieu carry-over storage of water at Cadiz, if CRA capacity was unexpectedly unavailable.



Physical Interconnection 

The Cadiz Water Project would enter the CRA at the termination of the project’s conveyance pipeline near Rice, CA. The EIR considered a variety of options to enter the CRA including the construction of a forebay or equalization reservoirs, as well as operational changes in the MWD system.  These various scenarios assumed final entry into the CRA would be determined by MWD in consultation with the Project’s participating agencies. There is no application yet before MWD related to the tie-in, but once the tie-in and wheeling terms are arranged, they will be subject to Board consideration.  We believe there are multiple benefits that can be secured by MWD upon making space reasonably available for the Cadiz Water supplies and having the flexibility of relying on the Cadiz project in both wet and dry years. The tie-in is described and analyzed in the Project’s Final Environmental Impact Report CH 3, Section 3.6.1.


Cadiz & MWD

The 1999 version of our Project envisioned MWD exclusively purchasing and storing water in the Cadiz Valley.  In 2002, MWD decided not to proceed with that project (called the Cadiz Valley Groundwater Storage & Dry Year Supply Program) and it did not go forward.  In that instance, MWD was the one and only participating agency and the lead agency in the CEQA/NEPA environmental review.


Today, MWD’s role is considerably different. The agency must establish terms to convey conserved water for agencies within its service area at their request in accordance with Water Code §1810 et seq.  We believe MWD staff will faithfully execute this responsibility at the appropriate time for the benefit of member agencies interested in making Cadiz Project supplies available in Southern California.


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