2026-06-26

Desalination in California, Part III:

What California Actually Needs

A Water Policy Series — June 2026

Introduction

The first article in this series established the technical baseline: desalination is the most expensive water supply tool California has, ecologically costly in ways that require active mitigation, and a structurally small contributor to the volume the state needs — but it is the one major tool that does not fail when the rain stops, which managed aquifer recharge, its cheapest and most ecologically generative rival, fundamentally does. The second traced who actually decides how much of each tool gets built, and found no one does, in any accountable sense — the proportion emerges from fragmented grant funding, asymmetric permitting friction, and which local board or private developer happens to act first, with the same pattern of fragmented, crisis-driven governance recurring at every larger scale, up through the Central Valley Project’s unresolved coordination dispute with the State Water Project and the Colorado River’s live, deadline-bound 2026 renegotiation. This article asks what follows from that diagnosis.

I. The Narrow Case for Desalination, Restated

It is worth being precise about what desalination’s justification actually is, because the loose version of the argument — “California needs more water, and the ocean is right there” — does not survive the first article’s numbers. A dozen Carlsbad-scale plants, an enormous and decades-long undertaking, would supply less than a tenth of the state’s projected 2040 supply gap, at two to six times the cost of every serious alternative.¹ That is not the argument for desalination. The argument is narrower and more defensible: managed aquifer recharge, recycling, conservation, and stormwater capture are all correlated with the same precipitation signal that climate change is making less reliable, and in California’s last sustained multi-year drought, the state recovered less than a third of what it lost and, even in the wet years immediately following, recharged only about a fifth of the remaining overdraft.² Desalination’s water supply does not depend on that signal. Its case is as a deliberately small, deliberately expensive insurance layer against exactly the years when every other tool in the portfolio runs dry at once — not as a primary lever, and not at the scale or cost structure California has so far built it.

II. The Gap Between Stated Policy and Actual Practice

California’s own Water Supply Strategy already states the correct sequencing: conservation, recycling, and stormwater and groundwater recharge first; desalination last, as a costly tool reserved for circumstances nothing else can address.³ If the state were actually following that sequencing, the second article’s findings would look different. They do not. Huntington Beach was pursued for years, and ultimately killed, not because a state body determined the Orange County coast needed fifty million gallons a day of drought insurance, but because a private developer identified a permitting pathway and a local market and pursued it.⁴ Carlsbad exists, and now binds San Diego County ratepayers to a fixed annual purchase through 2045 regardless of need, because a county water authority signed a contract whose long-term financial terms outlasted the drought conditions that motivated it.⁵ Neither outcome reflects the state’s stated logic. Both reflect what a private contractor could get a local board to agree to.

This is the sharper version of the critique this series has been building toward. The honest complaint about California’s desalination program is not that desalination is inherently wrong, or that the technology should be abandoned — Doheny’s subsurface intake design and careful aquifer modeling show the technology can be deployed with real care.⁶ The honest complaint is that the proportion of desalination California has built bears only a loose relationship to the proportion its own water plan says it should have, because nothing enforces that plan’s sequencing on the local boards and private developers who actually decide whether a plant gets built. The Ocean Plan regulates how a desalination plant must be built. Nothing regulates how many California should have, relative to the cheaper, more generative alternatives sitting beside it on every cost comparison in the state’s own literature.

III. Symptom, Not Cause

The second article’s wider lens matters here, because it shows that this is not a failure unique to desalination policy. The Central Valley Project and the State Water Project have operated under an unresolved coordination disagreement since 2015, reset by seven consecutive federal administrations, governing a Delta system that is oversubscribed by water-rights claims more than five times over.⁷ The Colorado River’s governing guidelines expire at the end of this year, in the worst hydrologic year on record for the basin, with Upper and Lower Basin states still disputing who absorbs climate-driven cuts to a river that has shrunk twenty percent in twenty-five years.⁸ At every scale examined in this series — a single coastal water district, the state’s two largest conveyance systems, an entire interstate river basin — the same structure recurs: multiple actors holding legally enforceable claims to a shrinking, oversubscribed resource, governed by agreements renegotiated in periodic crisis rather than adjusted continuously, with no single body accountable for the aggregate result.

Read this way, desalination and managed aquifer recharge are not really competing answers to “how does California get more water.” They are two of the ways individual actors respond to a system that will not reliably deliver water through its shared channels. Coastal and Southern California urban agencies build desalination plants because winning the annual Delta-export fight is not guaranteed and building a local, weather-independent supply removes that uncertainty, whatever its cost.⁹ Inland and Central Valley agricultural interests lean toward recharge because they already hold the land and aquifer access SGMA requires them to use, and because the state is actively paying them to repurpose acreage toward it as surface diversions are curtailed.¹⁰ Each choice is locally rational. Neither is being weighed against the other by anyone positioned to weigh the whole system — which is exactly why California keeps building expensive, parallel, single-purpose infrastructure instead of fixing the shared system underneath it.

IV. What Would Actually Move the Needle

The fixes already proposed by the people closest to each layer of this problem point in a consistent direction: toward governance and coordination, not new construction. The Public Policy Institute of California has proposed unifying the Central Valley Project and the State Water Project outright, eliminating the federal-state operational seam that neither agency has been able to resolve through negotiation since 2015.¹¹ On the Colorado River, the Upper Basin’s “supply-driven operations” proposal — tying reservoir releases directly to measured hydrologic conditions rather than fixed contractual entitlements — would replace the current cycle of crisis renegotiation with something closer to an automatic, continuously adjusting rule.¹² Within California, SB 72’s expansion of the Water Plan’s advisory committee to formally include Tribes, labor, and environmental justice representatives, and its requirement that DWR set a 2050 planning target treating tribal, agricultural, urban, and environmental uses as co-equal categories, is a modest but real step toward a process that actually weighs competing claims against each other rather than letting whichever board acts first set the outcome by default.¹³

None of these fixes require a single new treatment plant or recharge basin. They require California, and the federal government, to spend governance effort on the seams between water systems rather than only on the systems themselves — the same kind of investment, in different currency, that the state has already been willing to make in concrete and steel. The clearest failure in this series is not that California built a desalination plant it didn’t strictly need at Carlsbad, or that managed aquifer recharge can’t reach a drought it wasn’t built to reach. It is that the state has a stated, sensible answer for how much of each it should build, and no mechanism that connects that answer to what actually gets approved, financed, and operated on the ground.

Conclusion

California does not lack ideas for closing its water gap. It has a state water plan that correctly sequences cheap, multi-benefit tools ahead of expensive, narrow ones; a desalination technology that, deployed carefully, can avoid its worst ecological costs; a recharge strategy with genuine multi-decade success stories to draw on; and, increasingly, a legislative process willing to widen who gets a voice in the decision. What it lacks is a structure that makes any of that binding on the local boards, private contractors, and competing agencies who actually build things — the same structural gap that shows up, at larger scale, in the unresolved seam between its two biggest conveyance systems and in the interstate river negotiation now running up against a 2026 deadline. The tools to close California’s water gap, in something close to the proportion the state’s own strategy already recommends, exist. What is missing is not technology, and not money. It is a governance structure capable of deploying the tools it already has as a coordinated system, rather than as a series of separately negotiated, locally rational bets.

Footnotes

Sources

This Series

Desalination in California, Part I: The Scope of the Problem

Desalination in California, Part II: Who’s at the Table

Policy & Governance

CalMatters — How can California boost its water supply?; A salty dispute — calmatters.org

Public Policy Institute of California — Uniting the Central Valley Project and the State Water Project Would Benefit All Water Users — ppic.org

Congressional Research Service — Central Valley Project: Issues and Legislation — congress.gov

U.S. Bureau of Reclamation — Colorado River Post 2026 Operations — usbr.gov

High Country News — Why Colorado River negotiations are so difficult — hcn.org

Maven’s Notebook — Colorado River post-2026 operations: Lower Basin proposal and next steps — mavensnotebook.com

CalMatters Digital Democracy — SB 72 bill tracking — calmatters.digitaldemocracy.org

Reporting

Voice of San Diego — San Diegans Owe a Desal Company $35 million for Unmade Water — voiceofsandiego.org

South Coast Water District — Doheny Ocean Desalination Project — scwd.org

Knowable Magazine — Can desalination quench agriculture’s thirst? — knowablemagazine.org