Building Resilience

The Emergency Storage Program is a system of reservoirs, pipelines, and pump stations. After a disaster such as an earthquake, it is designed to provide member agencies with 75% of normal supply for up to two months with no imported water and up to six months with limited imports. Its effectiveness depends on the aqueduct system staying in operation.³ San Vicente Dam was raised 117 feet, more than doubling the reservoir's capacity. The Water Authority holds storage rights to 157,100 acre-feet of capacity there: 52,100 for emergencies and 105,000 for carryover storage in dry years.⁴

The most distinctive piece was a water supply source that does not depend on the fluctuations of seasonal drought, built through a public-private partnership. On December 20, 2012, the Water Authority entered a 30-year Water Purchase Agreement with Poseidon, the private developer of the Claude "Bud" Lewis Carlsbad Desalination Plant. Poseidon built the plant with the Water Authority committed to buy the produced water: 48,000 acre-feet a year, if available, on take-or-pay terms, with an option for 8,000 acre-feet more at a lower rate. Commercial operation began on December 23, 2015. The plant changed hands in 2019 and is now operated and maintained by Channelside Water Resources; the Water Authority owns the ten-mile pipeline that connects it to the regional system.⁹

The Water Authority calls it the nation's largest seawater desalination plant, with a capacity of about 50 million gallons a day.¹⁰ That reliability has a price, and the Water Authority chose to pay it. Its 2027 rate study puts the supply cost of Carlsbad water at $3,493 an acre-foot and Imperial Valley transfer water at $1,539, compared to $1,030 for untreated water from Metropolitan.¹¹ Metropolitan's supply is the cheapest of the three, but the other two are what the region added after 1991 so it would not be dependent on a single source. The region's ratepayers carry the difference, but stand to benefit from the flexibility those supplies provide.

A fixed Supply Reliability Charge bills every member agency for a quarter of the premium, $51.3 million for 2027, because, in the study's words, "access to reliable supply benefits all member agencies regardless of whether the agency purchases water every day or intermittently." The Water Authority's budget calls Carlsbad "a drought-proof local treated water supply." The premium works like an insurance payment, and the gap may be closing. The study expects Metropolitan's rate to rise faster than the cost of the region's own reliable supplies in 2028.¹²

Two agreements sit inside the 2003 Colorado River Quantification Settlement Agreement. The first, signed with the Imperial Irrigation District in 1998, transfers conserved water and ramps up to 200,000 acre-feet a year. The second secured 77,700 acre-feet a year saved by lining the All-American and Coachella canals, investments that the Water Authority and the State paid for jointly. The settlement requires the Water Authority to buy all 277,700 acre-feet every year on take-or-pay terms. The Imperial transfer runs to 2047 and can be extended 30 years by mutual agreement. The canal-lining water runs to 2112. The Water Authority describes the resulting supplies as tied to high-priority rights on the Colorado River.¹⁴

In February 2026 the Board unanimously approved an agreement to explore interstate water transfers and exchanges, and the parties have since executed it. The other parties are the Bureau of Reclamation, Metropolitan, the Southern Nevada Water Authority, the Arizona Department of Water Resources, Salt River Project, and the Central Arizona Water Conservation District. The agreement covers supplies produced by seawater desalination or advanced water purification, such as Carlsbad's, and exchanges would happen "on paper," through existing aqueducts. The Water Authority says such a program has never been achieved in the Lower Colorado River Basin. The agreement itself creates no financial benefit and commits no party to a project. In September the Water Authority reported that the parties are evaluating an initial pilot of about 10,000 acre-feet, and its bond disclosure that month named a goal of a first exchange as early as 2027.¹⁸

On August 21, the Secretary of the Interior signed a Record of Decision setting a ten-year framework for Lake Powell and Lake Mead, with operating guidelines for 2027 and 2028. The guidelines cut Lower Basin deliveries by 1.25 million acre-feet in each of those years. If Arizona, California, and Nevada implement their proposed sharing agreement, Arizona's share of the cut is 760,000 acre-feet a year, California's 440,000 (a tenth of its normal 4.4 million), and Nevada's 50,000. Without that agreement, the Secretary sets each state's share under applicable law.²⁰

The three states have until the new year to formalize that agreement. As of October 1st, they were still finalizing it, and California was still settling how its own water users would share the cut.²¹

In August the State of Nevada, the Colorado River Commission of Nevada, and the Southern Nevada Water Authority sued in federal court to set the decision aside.²²

Mexico has taken their own cuts. Under Minute 334, signed with the United States in September, its deliveries fall by 250,000 acre-feet a year in 2027 and 2028.²³