Executive Summary

California has one of the most remarkable systems of reservoirs and aqueducts in the world, capable of storing and transferring millions of acre-feet of fresh water every year from its northern lakes and rivers to its major agricultural and urban areas throughout the entire state. Even during the state’s normal cycles of drought years, this system has remained capable of supplying sufficient water to irrigate millions of acres of rich farmland and supply its urban centers. However, in recent decades, a significant percent of water supplies previously stored for agricultural and urban use has been mandated for release into the state’s rivers to protect the environment and species in the Sacramento-San Joaquin Delta.

This presents California with a choice. In order to protect aquatic species and ecosystems in the state, significant farm acreage can be fallowed, and urban water supplies can be rationed, or water supplies can be increased through investments in new projects. Failure to make these investments carries with it significant risks: a degraded environment and economic hardship that impacts all industries dependent on water, including agriculture and home building, and ripples through the broader economy.

California’s water supply is not only challenged by increased attention to environmental priorities, but also by the massive population growth in neighboring states that share water from the Colorado River. The growing water requirements in Arizona, Nevada, and other Colorado Basin states put pressure on California to reduce its reliance on water from the Colorado River.

What if water from the Colorado River was no longer available to Southern California? What if mandated reductions of surface water use and groundwater use become insufficient to meet the increasing demands of California’s agricultural industry because millions of acre feet of fresh water per year must be left as “unimpaired flow” in order to protect the ecosystems in the Sacramento San-Joaquin Delta? For that matter, what if a natural disaster such as a powerful earthquake were to destroy levees or damage aqueducts, cutting off the delivery of water from Northern California to Southern California through the State Water Project?

The answers are many and complex, but one is straightforward: If California has a severe water crisis, the nation will have an economic crisis. California leads America’s states in the generation of goods and services. Only four countries — the  US, China, Germany, and Japan¹ — have more economic output than the State of California. California leads the nation in agricultural production at home and in agricultural exports to the rest of the world. That agricultural production, however, requires approximately 40% of the State’s water. 

Even without the new priority to keep far more water in the state’s rivers and estuaries to protect the environment, California’s aging network of reservoirs, aqueducts, and pumps are increasingly vulnerable to structural failure, whether from natural disasters or merely the passage of time. Water insecurity has become the norm in California, and a threat to both the nation’s economic wellbeing and national security.

On paper, California has generated ideas about how to address its water supply challenges, acknowledging that its existing water supply for farms and cities could diminish by up to 10% by 2040.² As the potential for chronic water scarcity — or even a water crisis — increases in California, however, consequential action appears neither imminent nor apparent. For example, while California recognizes the importance of seawater desalination, the development of siting and other criteria has been delegated to a very sizeable group of regulatory and policymaking bodies,³ representing a variety of competing interests and priorities. One of those bodies, the State Water Resources Control Board, is considering potential amendments to the Seawater Desalination Provisions of the Water Quality Control Plan for Ocean Waters of California (the “Ocean Plan”).⁴ The Ocean Plan is notable because it was referenced by the Coastal Commission when the Commission denied a 2022 seawater desalination facility proposal, citing, among other things, concerns related to sea level rise, environmental justice, and wetlands. At this point, there are no indications that the group of California agencies working on the regulatory standards for seawater desalination facilities is considering a viable, streamlined process for the siting of large (e.g., production of 50,000 acre-feet of fresh water per year or more) seawater desalination facilities along the California coast.

The federal government, however, has the opportunity to protect the national interest by cooperating with local water agencies to facilitate the construction of seawater desalination facilities on federal lands along the California coast. Seawater desalination is a proven technology that today delivers over 40 million acre-feet of fresh water every year throughout the world. Saudi Arabia alone produces 3.5 million acre-feet of fresh water each year, with one complex in Saudi Arabia, operated by the Saline Water Conversion Corporation, producing nearly 900,000 acre-feet of fresh water per year, the product of eight interconnected plants. This is possible in California.

This report will address opportunities for the federal government to facilitate the development of seawater desalination facilities on federal lands along the California Coast through a streamlined federal, rather than State, process. Without focusing on any specific location or facility, this report will outline possible options for achieving this objective. 

Option A: Use existing federal authority under the Coastal Zone Management Act (CZMA) and the Submerged Lands Act (SLA) to allow major seawater desalination facilities on federal lands along the California Coast. In this scenario, minor amendments to these statutes, and to their implementing regulations, could clarify and streamline the approval process.

Incidental to Option A: A Presidential Executive Order could provide clarification to and/or override existing federal regulations implementing the CZMA and the SLA in order to facilitate a streamlined approval process.

Option B: Enact federal legislation which declares that matters related to the siting and regulation of seawater desalination facilities along the nation’s coast raise significant issues with respect to national security, interstate commerce, and international trade and that, therefore, the federal government preempts all state and local laws, requirements, regulations, and/or standards related to the siting, permitting, operation, and use of seawater desalination plants on coastal federal lands.

In short, the CZMA and the SLA are often seen as impediments to seawater desalination projects on coastal federal lands. Perhaps overlooked, these statutes also contain provisions that allow the federal government to exercise its “paramount” rights and interest in matters pertaining to interstate commerce, international trade, and national security. These rights can support the construction of seawater desalination facilities on coastal federal lands and across state-controlled submerged lands when tied to interstate or international commerce—such as maintaining California’s critical agricultural exports and overall economic vitality.

The assertion of existing legal authority, accompanied by targeted legislative and administrative action, will make large-scale seawater desalination feasible along California’s coast. By ensuring a secure, sustainable water supply for California, the federal government will fulfill its obligation to protect the nation’s interests in commerce and national security.

Introduction

Assuring water security in California will prevent a national emergency. Seawater desalination is a proven and compelling technology that today delivers over 40 million acre-feet of fresh water worldwide every year, with capacity rapidly growing everywhere from the Middle East to Singapore and Western Australia. A single seawater desalination complex in Saudi Arabia, operated by the Saline Water Conversion Corporation, produces nearly 900,000 acre-feet of fresh water per year, the product of eight interconnected plants each producing over 100,000 acre-feet of fresh water per year. In all, just one nation, Saudi Arabia, uses seawater desalination to produce 3.5 million acre-feet of fresh water per year.

California can do the same. Modern technologies to access seawater and disburse brine from desalination can ensure minimal impacts to the marine environment. In terms of energy consumption, just the 2.0 gigawatts output of California’s one remaining nuclear power plant, Diablo Canyon, would be sufficient for seawater desalination plants to produce five million acre-feet of fresh water per year.

To put this into perspective, California’s total urban water consumption, serving 37 million people, averages only 8 million acre-feet of fresh water per year. Large-scale seawater desalination, combined with local runoff and wastewater treatment, could easily render California’s cities independent of imported water, greatly improving the state’s water security. Moreover, large-scale seawater desalination in California has the potential to greatly reduce the state’s dependence on water from the Colorado River, thus increasing the available water supply in Arizona and Nevada.

Finally, the investment required to develop large-scale seawater desalination is competitive with the cost to develop other water supply options. Wastewater recycling plants, a promising and necessary corollary to desalination, now approach construction cost parity with seawater desalination due to expensive new requirements to remove from the waste stream microplastics and per- and polyfluoroalkyl substances (PFAS), a group of persistent chemicals. Similarly comparable is the cost to build new reservoirs large enough to yield additional millions of acre-feet of fresh water per year.

We have identified two principal options for streamlining the process for constructing seawater desalination plants along California’s coast. Our focus is upon projects that would be deemed a “federal activity” on a combination of (i) federal property landward of the mean high tide line and (ii) State property seaward of that line which was obtained pursuant to the Submerged Lands Act (SLA). The State’s regulatory authority is based on the Coastal Zone Management Act (CZMA). The two options for consideration are:

Option A: On the surface, both the CZMA and the SLA present obstacles to the construction of major seawater desalination facilities along California’s coast. Nonetheless, they also present opportunities to do so on federal lands without the approval of California regulators where the “paramount” interests of the federal government are concerned. The challenge, however, is that the process is cumbersome and might require, at a minimum, adjusting administrative regulations. Better yet, the authority to invoke this process may be strengthened and streamlined through amendments to the statutes, modifications to their implementing regulations, and direct Presidential action, all of which are outlined below.

Option B: The Constitution’s “Supremacy Clause” may provide Congress the opportunity to enact legislation through which the federal government preempts all state and local laws, requirements, regulations, and/or standards related to the siting, permitting, operation, and use of seawater desalination plants. The stated justification, arguably more of a political than a legal requirement, declares that matters related to the siting and regulation of seawater desalination facilities along the nation’s coast raise significant issues with respect to national security, interstate commerce, and international trade.

The analysis leading to these recommended options is as follows:

Current Constraints on Coastal Seawater Desalination Facility Development in California

Currently, the rights of the federal government to construct seawater desalination facilities, even on federal coastal lands in California, are generally limited by the following:

• The SLA granted coastal states “vested” title to lands below the mean high tide line and extending three nautical miles into the sea. Limited exceptions along the California coast have resulted from cession to, or re-acquisition by, the federal government.
• The intake (and typically the waste/outflow) components of a seawater desalination plant, whether above or below the ocean floor, require the use of lands and/or waters which generally belong to the State as a result of the SLA.
• As a result, in California, absent applicable exemptions and exceptions, if State-owned land is needed for the intake/outflow components, then, at a minimum, a lease of State land from the State Lands Commission and a positive CZMA  “consistency determination” from the Coastal Commission typically are needed. A Coastal Development Permit from the Coastal Commission may also be required. 
• The Coastal Commission makes a ”consistency determination” based upon the policies found in Chapter 3 of the California Coastal Act. An adverse consistency determination can — and generally does — mean that the project will not be built. A great deal of subjectivity goes into that consistency determination.
• As an example, in 2022, the Coastal Commission specifically referenced the California Ocean Plan,⁵ sea level rise, environmental justice, and wetlands as grounds for an adverse consistency determination that doomed the Poseidon seawater desalination project in Huntington Beach. 
• While federal lands technically are not within the CZMA’s “coastal zone,” federal activity on federal lands may still require a consistency determination if it impacts property not owned by the federal government, but which is located within the Coastal Act’s “coastal zone” (which differs from the CZMA “coastal zone”).
• In making its consistency determinations, the Coastal Commission does not consider private projects on federal lands to be “federal activity” to be exempt from the CZMA (e.g., Space X/Vandenberg AFB). This derives from §930.31(a) of the federal regulations implementing the CZMA which excludes from the definition of “Federal agency activity” the issuance of a license or permit by the federal government “to an applicant or person.”
• For federal projects, the National Environmental Policy Act (NEPA) of 1969 will require environmental review of the proposed project. The federal Environmental Species Act could potentially come into play depending upon the specifics of the proposed project. In addition, depending upon the context of the project, the California Environmental Quality Act (CEQA) might possibly be triggered.

The Scope of the Federal Government’s Right to Construct Seawater Desalination Plants on Coastal Federal Lands

With minor modifications, available procedures under both the CZMA and the SLA can facilitate approval of federal activities on federal lands without needing to comply with California’s regulatory processes.

Federal Actions to Bring Seawater Desalination to Coastal California

OPTION A – FEDERAL PRIMACY UNDER EXISTING FEDERAL LAW

Provisions within the Coastal Zone Management Act (CZMA): Currently, even though the State, through the Coastal Commission or otherwise, can object under the CZMA, the CZMA does not give states unlimited regulatory authority over federal activity. To the contrary, even if the Coastal Commission makes an adverse “consistency determination,” the CZMA allows the federal agency to choose to continue the proposed activity. If it does so, however, the State can then litigate or request that the Secretary of Commerce mediate. Ultimately, even if a court upholds the Commission’s objection, the President may exempt a federal agency activity if the President determines that the activity is in the paramount interest of the United States. While this creates an option which avoids State review, it is unfortunate that a costly and lengthy process must come before the President to provide the exemption. 

SOLUTION:  

• Moving the Presidential exemption to the beginning of the process would logically save considerable time and expense for all parties.
• Amending the CZMA and its regulations to clarify that federal agency activity includes activities where the federal government is permitting or assisting the actions of private or state parties would remove State oversight for projects involving third parties on federal lands which are authorized and/or assisted by the federal government.

Provisions Within the Submerged Lands Act (SLA): Currently, the SLA allows the federal government to surpass the State’s rights even where the project involves State land acquired through the SLA. Section 1314(a) of the SLA provides that the federal government’s “constitutional purposes of commerce, navigation, national defense, and international affairs” are “paramount” to the rights of the states. You can analogize this reserved sovereign power to a seller reserving an easement over property upon sale of that property to a new owner. The new owner’s title is subject to that easement. Similarly, the State’s property rights under the SLA do not prevail over the federal government’s stated “paramount” rights. So, because interstate and international commerce are significantly impacted by the viability of California’s economy, steps necessary to assuring the long-term delivery of water to nourish that economy are essential to maintaining the federal government’s paramount interest in commerce.

Section 1314(b) of the SLA provides a second, though less practical, option for overcoming the State’s SLA property rights by reserving the right to condemn the State property “in time of war or when necessary for national defense,” subject to the payment of “just compensation.” 

SOLUTION: Invoking the federal government’s reserved constitutional “commerce” rights would override the State’s tidelands ownership rights.

The “Commerce” Argument: The “commerce” justification for invoking the Paramount right of the federal government would be along these lines:

• The 1947 US Supreme Court decision in U.S. v. State of California, 332 U.S. 19, held that the federal government, not California, owned the tidelands and resources off the California coast.
• In a legislative response to that Supreme Court decision, the SLA of 1953 vested in the states title to the submerged tidelands and resources.
• The SLA did not alter the holding in U.S. v. State of California, but rather statutorily conveyed to the states tidelands which previously were owned by the federal government.
• That conveyance, however, was subject to a reservation contained in Section 1314(a) of the SLA which reads:

The United States retains all its navigational servitude and rights in and powers of regulation and control of said lands and navigable waters for the constitutional purposes of commerce, navigation, national defense, and international affairs, all of which shall be paramount to, but shall not be deemed to include, proprietary rights of ownership, or the rights of management, administration, leasing, use, and development of the lands and natural resources which are specifically recognized, confirmed, established, and vested in and assigned to the respective States and others by section 3 of this Act.

• The wording of Section 1314(a) relates back to a statement in the U.S. v. State of California decision:

The ocean, even its three-mile belt, is thus of vital consequence to the nation in its desire to engage in commerce and to live in peace with the world; it also becomes of crucial importance should it ever again become impossible to preserve that peace. And as peace and world commerce are the paramount responsibilities of the nation, rather than an individual state, so, if wars come, they must be fought by the nation. 

While the Supreme Court majority clearly focused on world commerce, in his dissenting opinion, Justice Frankfurter agreed that the U.S. had “’paramount rights’ in the sea belt of California” that were “implied by the power to regulate interstate and foreign commerce.” So, California’s critical role in both international and interstate commerce appears to provide justification for exercise of the federal government’s paramount rights.

• To further tie seawater desalination to world commerce, here’s some basic numbers to consider from the Governor’s Office of Business and Economic Development, US Department of Agriculture (USDA), and others:
• 9% of all US exports are from California.
• California handles more than $674 billion in exports and imports and ranks first among states in agricultural exports.
• California’s agricultural sector uses approximately 40% of the state’s water.
• Drought significantly impacts California’s agricultural water supply by diminishing surface water from major conveyance projects, increasing dependence on groundwater, and raising crop water demands due to higher temperatures. These factors lead to economic losses for farmers and heighten the urgency for sustainable water management strategies. 

Therefore, the premise of the commerce argument is as follows: Coastal seawater desalination facilities, particularly in Southern California, will result in a redistribution of water within the State to increase the amount of water available to California’s agricultural sector (likely a critical claim) which, in turn, will serve the nation’s interests in the ongoing production of agricultural products for international trade. Absent increased water supply, the agricultural sector and international trade will suffer.

This argument is furthered by documenting the water-intensive industries (including food processing and manufacturing) in California apart from farming. Even data centers, a growing industrial priority in the U.S., exports information worldwide, and it is in the national interest to keep data centers in America.

Therefore, seawater desalination facilities on federal lands will protect California’s critical agricultural sector and other industrial sectors, which are of critical importance to interstate and international commerce. This, then, allows the federal government to exercise its Section 1314(a) reserved paramount powers. 

This rationale could, of course, be expanded to other key California industries critical to interstate and international commerce.

By exercising its paramount rights, the federal government could remove the State from the approval process and avoid the need for a lease of State tidelands.

Legislative Amendments to the CZMA and the SLA

These opportunities under the existing terms of the CZMA and the SLA can be streamlined significantly through the following:

The CZMA:

• Define a “federal activity,” whether in whole or in part on federal lands, to include infrastructure, utility, and other (e.g., military and national security) projects authorized by the federal government, in partnership with non-federal agencies and/or private entities, or otherwise assisted by the federal government.
• Exempt from the CZMA the approval of a federal activity (or at least a seawater desalination facility on coastal federal lands).
• Rather than intervene later in the process as is now the case, create an early exemption process which would allow the President and/or the Secretary of Commerce to exempt from State review any federal activity deemed to be in the national interest within 120 days after an application for exemption is filed with the Department of Commerce.

In addition, corresponding changes must be made to the Code of Federal Regulations, Title 15, Subtitle B, Chapter IX, Subchapter B, Part 930 to implement the proposed CZMA changes.

The SLA:⁶

Amend 43 USC § 1314(b) to authorize federal condemnation of submerged State lands for purposes of commerce (in addition to war and national defense). 

• Amend the definition of “natural resources” in 43 USC § 1301(e) to exclude water used for consumption. This would limit the State’s right to assert control over the ocean water. 
• Specifically provide that the “paramount” rights reserved by the United States may be established by order/declaration of the President of the United States and/or, depending upon the specific “purpose” of the order, the appropriate Cabinet Secretary  (i.e., Commerce, Interior, Navy, Defense, State, etc.).

OPTION B – FEDERAL PREEMPTION

Under Option B, Congress would enact new legislation declaring that matters related to seawater desalination facilities along the nation’s coast raise significant issues with respect to national security, interstate commerce, and international trade. For those reasons, with a “notwithstanding the CZMA and the SLA” preface, the federal government would preempt all state and local laws, requirements, regulations, and/or standards related to the siting, permitting, operation, and use of seawater desalination plants on coastal federal lands. This legislation also would provide for the preparation of regulations creating a streamlined federal permitting process for the construction of seawater desalination facilities (i) by, with the authorization of, in partnership with, or assisted by the federal government, (ii) in coastal areas within the United States, and (iii) on federal lands and/or lands over which the federal government has “paramount” rights. 

BOTH OPTIONS – RELATED ACTIONS

Actions supporting both Option A and Option B should include:

• Amending NEPA and the Endangered Species Act (ESA) to exempt or categorically exclude from (or significantly limit) review major federal infrastructure projects related to critically-needed water supplies, including the construction of seawater desalination facilities. Projects likely could be approved without an exemption or exclusion, but the process would be far more costly, time-consuming, and cumbersome.
• Issuance by the Department of Interior of guidance clarifying that:
• Seawater for purposes of desalination is not a “natural resource,” consistent with the use of water for hydroelectric applications and distinct from the classes of resources listed in the SLA (generally related to mining and fishing operations).
• The “United States” includes activities done in partnership with federal, state, and/or local agencies, as well as with private entities. 
• Seawater is an “article of commerce,” thereby limiting California’s ability to regulate its transfer between states, building on the authority of Sporhase v. Nebraska ex rel. Douglas (1991) 458 U.S. 941, which recognizes groundwater and surface water as articles of commerce.
• The Department of the Navy could be directed to inventory all federally-owned lands suitable for seawater desalination projects along the California coast, particularly where the “submerged lands” are owned by the federal government (e.g., those beneath existing federal naval bases / harbors).

Conclusion

California’s historic and ongoing strategy of mandated water scarcity affects more than just Californians. It is a national security issue. The state’s agricultural sector is a vital contribution to America’s food supply and exports. Its tech and industrial output are critical to global commerce, and yet 25 million Southern California residents depend on a neglected and vulnerable water supply infrastructure. Large-scale seawater desalination is a solution that will improve California’s resilience and serve national interests in commerce, security, and environmental sustainability.

When viewed through the lens of global commerce, desalinated seawater will support export-heavy agriculture, reduce dependence on overdrawn, multi-state river systems like the Colorado River, and ensure the continuity of industrial sectors with global reach. Whether through cyberattack, other civil disruptions, scarcity mandates, natural disasters, or drought, the disruption of California’s water supply would send economic shockwaves far beyond the State’s borders.

We believe the steps the federal government can take, as described in this analysis, have the potential to overcome State obstacles to large-scale seawater desalination along California’s coast.

Endnotes

•  Source: IMF World Economic Outlook Database, US Bureau of Economic Analysis, 2025.
•  California’s Water Supply Strategy: Adapting to a Hotter, Drier Future, Aug 2022.
•  On Page 2 of a December 2023 report of the California Seawater Desalination Interagency Group, those bodies include “the State Water Resources Control Board (State Water Board), the California Coastal Commission (Coastal Commission), the California State Lands Commission (State Lands), the California Department of Fish and Wildlife (Fish and Wildlife), Monterey Bay National Marine Sanctuary (MBNMS), the National Marine Fisheries Service’s (NMFS) West Coast Region, and the six coastal regional water quality control boards (regional water boards), which include the North Coast Regional Water Quality Control Board, the San Francisco Bay Regional Water Quality Control Board, the Central Coast Regional Water Quality Control Board, the Los Angeles Regional Water Quality Control Board, the Santa Ana Regional Water Quality Control Board, and the San Diego Regional Water Quality Control Board, with additional representation from: California Ocean Protection Council (Ocean Protection Council), California Natural Resources Agency, California Department of Water Resources (Department of Water Resources), and California State Coastal Conservancy (Coastal Conservancy).”
• The Ocean Plan is authorized by the California Water Code. It deals directly with desalination plants. Potential amendments to the Ocean Plan specific to desalination plants appear to remain pending. These focus upon (i) integrated management to support use of desalinated water, (ii) engagement with the Tribes, (iii) human right to water, racial equality, and environmental justice, (iv) a uniform approach to controlling adverse effects of desalination facilities, and (v) improving planning and permitting efficiency.
• The Ocean Plan is authorized by the California Water Code. It deals directly with desalination plants. Potential amendments to the Ocean Plan specific to desalination plants appear to remain pending. These focus upon (i) integrated management to support use of desalinated water, (ii) engagement with the Tribes, (iii) human right to water, racial equality, and environmental justice, (iv) a uniform approach to controlling adverse effects of desalination facilities, and (v) improving planning and permitting efficiency.
•  Where arguably appropriate, these amendments would be stated to be declarative of existing law and original legislative intent.

About the Authors

Edward Ring is the Director of Water and Energy Policy at the California Policy Center, which he co-founded in 2013. Ring is the author of Fixing California: Abundance, Pragmatism, Optimism (2021) and The Abundance Choice: Our Fight for More Water in California (2022).

Ed@CalPolicyCenter.org, 916.718.8572
California Policy Center
18002 Irvine Boulevard, Suite 108, Tustin, California 92780

Tim Paone is a partner in the Land Use & Natural Resources group at Cox Castle & Nicholson. For more than four decades, he has represented landowners and developers in complex California entitlement matters, focusing on CEQA, the Coastal Act, development agreements, and land use litigation.

TPaone@CoxCastle.com, 949.260.4655
Cox, Castle & Nicholson LLP
3121 Michelson Drive, Suite 200, Irvine, California 92612

About the District

Founded on January 1, 1960, and governed by a publicly elected, five-member Board of Directors, Mesa Water is an independent special district that provides water service to 110,000 residents in an 18-square-mile service area that includes most of Costa Mesa, a portion of Newport Beach, and John Wayne Airport. Mesa Water provides 100 percent local reliable groundwater to its customers due to the Mesa Water Reliability Facility.

Mesa Water District

MesaWater.org,949.631.1205

1965 Placentia Ave.

Costa Mesa, California 92627