Mojave Groundwater Bank
The Mojave Groundwater Bank is a water supply and storage project designed to conserve fresh groundwater before it becomes saline and evaporates, and bank water in wet years for use in dry years. Cadiz, public water agencies, and Native American Tribes are developing it to expand access to clean, reliable, and affordable water in Southern California and the Southwest.
Mojave Groundwater Bank
The Mojave Groundwater Bank is a water supply and storage project designed to conserve fresh groundwater before it becomes saline and evaporates, and bank water in wet years for use in dry years. Cadiz, public water agencies, and Native American Tribes are developing it to expand access to clean, reliable, and affordable water in Southern California and the Southwest.
What Is the Mojave Groundwater Bank?
Anchored at the base of a 2,000-square-mile watershed in the Mojave Desert, the project draws on one of the largest known freshwater aquifers in the nation, estimated to hold over 30 million acre-feet of high-quality groundwater. Rain and snow in surrounding mountains reaching above 7,500 feet replenish the system as groundwater slowly moves toward the dry lakes.
Its safe-yield plan provides for 2.5 million acre-feet of water supply over 50 years, averaging 50,000 acre-feet annually, less than 0.2% of that groundwater storage each year. That annual supply could meet the annual water needs of roughly 400,000 people. A separate phase offers storage for up to 1 million acre-feet of imported water.
Two pipelines would connect the supply to regional systems: the 220-mile Northern Pipeline, an existing natural-gas line approved for conversion across federal lands, and the planned 43-mile Southern Pipeline to the Colorado River Aqueduct.
30+ million acre-feet estimated in storage; up to 1 million acre-feet of planned storage
Water for ~400,000 people a year
How Does the Mojave Groundwater Bank Conserve Water?
The project would conserve water by managing the aquifer system and intercepting fresh groundwater moving through Fenner Gap before it reaches the Bristol and Cadiz Dry Lakes, becomes saline, and evaporates. Rain and snow recharge the aquifer, and groundwater slowly moves toward these low points in the desert basin.
The conservation plan draws on natural aquifer recharge and recovers fresh groundwater already moving from underground storage toward the dry lakes.
Once the system is managed, storing imported water underground would save surplus supplies for dry periods without the exposed surface of an open reservoir. Both phases would help agencies manage wet and dry years.
What the Mojave Groundwater Bank Offers
- Natural storage: Cadiz estimates the aquifer system’s storage exceeds Lake Mead’s full capacity. Groundwater beneath the dry lakes is about ten times saltier than the Pacific Ocean. Intercepting fresh water upstream would conserve it for beneficial use.
- Managed supply: The safe-yield plan provides for an average annual supply of 50,000 acre-feet over 50 years, with up to 75,000 acre-feet in a single year. The Groundwater Management, Monitoring and Mitigation Plan provides monitoring and corrective measures, including authority to reduce or stop pumping.
- Community commitments: San Bernardino County has a one-time 25,000-acre-foot allocation for delivery through planned infrastructure. Cadiz’s community agreements include up to 1,500 acre-feet annually for 50 years for the Torres Martinez Desert Cahuilla Indians at no cost. Cadiz-funded ATEC treatment systems support clean-water access at Torres Martinez Desert Cahuilla Indians’ facilities near the Salton Sea.
- Environmental review: California courts upheld the environmental review. The court rulings preserved the state approvals. Federal Northern Pipeline authorization followed in July 2026, followed by guaranteed maximum price contracts for principal construction work.
- Technical oversight: The management plan assigns advisory review to a three-member Technical Review Panel, while San Bernardino County retains final oversight decisions.
- Regional reach: The Northern Pipeline would serve San Bernardino County and State Water Project-dependent communities. Contracts cover approximately 22,000 acre-feet annually for Southern California providers. The Southern Pipeline would serve Colorado River users, including a proposed Arizona exchange. The U.S. Bureau of Reclamation’s funded review evaluates potential exchanges and supply capability.
Who Owns the Mojave Groundwater Bank?
Cadiz is one partner alongside public agencies and Tribal partners. Mojave Water Infrastructure Company, LLC (MWI) was formed by Cadiz to construct, own, and operate the project infrastructure.
Lytton Rancheria of California, a federally recognized Native American Tribe, committed up to $51 million in convertible financing as the project’s first Tribal investor. The financing supports development and provides a path to equity in MWI.
Fenner Valley Water Authority provides public oversight of project operations and facility maintenance. Its proposed lease-based framework covers facility maintenance and oversight of operations.
Mojave Groundwater Bank’s Path to Delivery
The Mojave Groundwater Bank combines groundwater management, conservation and storage with delivery infrastructure. State environmental approvals, federal pipeline authorization, and construction contracts are recent milestones that have advanced its development.
Final regulatory review, engineering, and construction financing are the next steps toward final delivery arrangements and construction of the Northern Pipeline, which is expected to be the first conveyance pipeline online.
In March 2026, the project applied to the California State Lands Commission for authorization to convey water across state-managed lands and for the finding required by California Water Code Section 1815. The application is being processed. In its August 2026 update letter to shareholders, Cadiz reported funding the work of a contractor selected by Commission staff to review the project’s environmental record and prepare a report to satisfy the applicable SLC requirements.
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Frequently Asked Questions
How much will the Mojave Groundwater Bank cost to build?
Cadiz projected approximately $1.5 billion with all facilities online in its August 2026 shareholder letter ($400M for Northern Pipeline and $1.1B for Southern Pipeline). The estimate includes all expenses for construction of a wellfield, the two pipelines, and ancillary facilities including power facilities, access roads, and pump stations.
How much water can the project deliver?
The project’s safe-yield plan provides for 2.5 million acre-feet of groundwater supply over 50 years, averaging 50,000 acre-feet annually. Actual deliveries depend on conveyance infrastructure, agreements, groundwater management safeguards, as well as cyclical fluctuations between wet and dry years.
How much has Lytton Rancheria committed to the Mojave Groundwater Bank?
Cadiz announced an October 2025 agreement providing up to $51 million in loan financing from Lytton Rancheria, convertible into interests in Mojave Water Infrastructure Company, LLC (MWI). The financing supports development and construction, with draws and equity conversion subject to the agreement’s terms.
Did courts review the project’s environmental impact report?
Yes. The Final environmental impact report was certified in 2012, upheld at trial in 2014, and sustained on appeal in 2016. Subsequent Addenda in 2019 and 2025 for project modifications were not challenged in Court.
Will Arizona receive water from the Mojave Groundwater Bank?
Central Arizona Irrigation and Drainage District signed a July 2026 memorandum of understanding for up to 10,000 acre-feet annually from the project. Delivery remains conditional on offtake and exchange agreements and pipeline construction.
How does imported-water storage differ from the project’s groundwater supply?
The planned storage phase would bank up to 1 million acre-feet of imported water for later use. That capacity is in addition to and separate from the annual groundwater supply provided for under the project’s 50-year safe-yield plan.