- Arizona is preparing to use stored water as Colorado River shortages deepen.
- California is paying farmers to conserve water and protect Lake Mead.
- Nevada’s restrictions on watering decorative grass take effect January 1, 2027.
- Phoenix, Mesa, and Southern California communities are developing alternative water supplies.
- The three Lower Basin states face proposed reductions totaling 1.25 million acre-feet annually in 2027 and 2028.
Friday, October 9, 2026 — The Colorado River’s new water year began October 1, 2026, and Arizona, California, and Nevada are preparing for another period of reduced water supplies.
The three states, known as the Lower Basin states, are responding in different ways. Arizona is preparing to draw on water it stored during wetter years. California is paying farmers to reduce irrigation. Nevada is preparing to enforce new restrictions on watering decorative grass.
Cities are also making changes. Phoenix has invested in pipelines that can move alternative water supplies to neighborhoods. Mesa is studying advanced water treatment. Southern California water agencies are expanding conservation and water storage programs.
Under federal operating guidelines announced August 21, 2026, the Lower Basin states face combined reductions of 1.25 million acre-feet annually in 2027 and 2028.
A proposed agreement would divide those reductions into 760,000 acre-feet for Arizona, 440,000 acre-feet for California, and 50,000 acre-feet for Nevada.
An acre-foot is enough water to cover one acre of land one foot deep, or approximately 326,000 gallons.
The reductions are tied to calendar-year operations beginning in January 2027, rather than the October 1 start of the water year.
Arizona: Using Water Saved for a Dry Future.
Arizona’s preparations include a major change in how the state uses its underground water reserves.
For decades, the Arizona Water Banking Authority stored Colorado River water underground, building reserves that could be recovered during shortages.
Now, the state is preparing to make more of those stored-water credits available.
On July 17, 2026, the authority approved extending its shortage-management approach through 2027. The Arizona Department of Water Resources has warned that additional reductions could affect urban customers of the Central Arizona Project.
The Central Arizona Project is the canal system that carries Colorado River water into central and southern Arizona, supplying cities, farms, and Tribal communities.
The state’s preparations also include proposals to reduce agricultural water use. Farmers and irrigation districts have submitted projects involving temporary fallowing, crop changes, and other conservation measures.
Fallowing means leaving farmland unirrigated for a period of time so the water can be conserved.
Some of these projects could create conserved-water credits that remain in the Colorado River system. However, proposals still require review and approval before their savings can be counted.
Phoenix and Mesa Prepare for Less River Water.
Phoenix has spent years preparing for interruptions in Colorado River deliveries.
Its water system draws from several sources, including the Salt and Verde rivers, the Colorado River, and groundwater.
The city’s drought pipeline infrastructure helps move water from other sources into areas that have depended heavily on Colorado River supplies.
Mesa is examining another option: turning highly treated wastewater into a potential future drinking-water supply.
The city already reuses treated wastewater for purposes that do not require drinking water. Its longer-term planning includes advanced purification technology and possible cooperation with Phoenix on a regional treatment project.
A potential project involving the 91st Avenue wastewater treatment facility remains under consideration.
These measures would help the cities manage reduced Colorado River deliveries, although proposed treatment facilities are not yet operating replacements for those supplies.
California: Paying Farmers to Leave Water in Lake Mead.
California’s approach includes paying agricultural water users to conserve water and expanding programs that help Southern California communities prepare for shortages.
The Imperial Irrigation District, which serves a major agricultural region in southeastern California, operated a program in 2026 that paid eligible growers $334 for each acre-foot of water conserved.
Participating farmers could temporarily stop irrigating certain fields of alfalfa and other grasses for 45 or 60 days.
The program ran from June through September. The conserved water could remain in Lake Mead rather than being used for irrigation.
The district reported conserving approximately 726,000 acre-feet through its conservation programs in 2025. That figure represents several conservation efforts, not just temporary irrigation reductions.
Coachella Valley Extends Conservation Through 2028.
The Coachella Valley Water District has extended its voluntary agricultural conservation program through 2028.
Under the program, eligible farmers can receive $275 for each acre-foot of water conserved. The program provides for up to 10,000 acre-feet of conservation annually.
Participants must demonstrate actual reductions in water use. They cannot simply replace Colorado River water with groundwater and claim the difference as savings.
The application period for the 2027 and 2028 program closed August 31, 2026.
Southern California Cities Seek More Flexibility.
The Metropolitan Water District of Southern California supplies imported water to agencies serving communities across the region, including Los Angeles, San Diego, Anaheim, and Riverside.
On July 14, 2026, Metropolitan approved an agreement with the Bureau of Reclamation to leave up to 200,000 acre-feet of Colorado River water in Lake Mead during 2026.
The district also approved conservation agreements involving the Quechan Tribe and Bard Water District that could save up to 19,000 acre-feet annually in 2027 and 2028.
Metropolitan has invested in water conservation, storage, and local water supplies to reduce the region’s dependence on imported water.
Those programs give Southern California water agencies additional options as Colorado River deliveries become less dependable.
Nevada: Removing Grass and Protecting Stored Water.
Nevada receives a much smaller share of Colorado River water than Arizona or California. Most of that water supports communities in the Las Vegas Valley.
The Southern Nevada Water Authority has concentrated much of its conservation work on reducing outdoor water use.
Its programs include payments for replacing grass with desert landscaping, seasonal watering restrictions, and incentives for businesses to install water-efficient equipment.
The authority reports that per-person water use declined by 58% between 2002 and 2025.
Las Vegas Faces a January 2027 Deadline.
Beginning January 1, 2027, Nevada law generally prohibits using Colorado River water to irrigate nonfunctional grass on properties not used exclusively for single-family residences.
The restrictions affect decorative grass at many commercial properties, apartment complexes, homeowners association common areas, and government facilities.
Grass used for recreation, including certain parks and sports fields, can remain.
The law also provides for certain exemptions and extensions.
The Southern Nevada Water Authority has encouraged property owners to replace decorative lawns with landscaping that requires less water.
Henderson and Other Communities Share the Effort.
Las Vegas is not the only community affected.
Henderson, North Las Vegas, Boulder City, and other Southern Nevada communities participate in regional water conservation and supply planning.
The region also has infrastructure designed to keep water flowing from Lake Mead when reservoir levels are unusually low.
Its third drinking-water intake and Low Lake Level Pumping Station allow Southern Nevada to withdraw water at elevations that could affect older facilities.
The pumping facilities do not create additional water. They help protect access to the supplies already available.
Nevada also maintains stored-water reserves in Arizona, California, and the Colorado River system that can help manage future shortages.
Negotiations Continue Over Future Reductions.
The immediate preparations come as the seven Colorado River Basin states continue discussing how to manage the river beyond 2028.
On August 21, 2026, the Department of the Interior issued new operating guidelines for 2027 and 2028, along with a broader decision framework extending through 2036.
The guidelines require the Lower Basin states to reduce deliveries by a combined 1.25 million acre-feet annually for the next two calendar years.
They also provide for at least 700,000 acre-feet of additional voluntary conservation and storage over that period.
The state-by-state division remains tied to implementation of the Lower Basin states’ proposed sharing agreement.
Nevada has challenged aspects of the federal decision in court, arguing that future operating rules could require much larger reductions from the state.
Arizona and California are also negotiating how future shortages should be shared.
The federal framework allows operating rules to be revisited as conditions change and negotiations continue.
For now, water agencies are preparing for the reductions scheduled to begin in January 2027. Their responses range from withdrawing stored groundwater and paying farmers to conserve water to expanding water recycling and removing decorative grass.
The coming year will bring new operating requirements for the Colorado River, along with continued decisions about how its limited supplies will be divided among farms, cities, and other water users.
Sources and Citations
- U.S. Department of the Interior. 2027–2028 Colorado River Operating Guidelines. August 21, 2026.
https://www.doi.gov/node/67716
- Arizona Department of Water Resources. The Arizona Water Banking Authority Undergoes a Change of Direction. September 23, 2026.
https://www.azwater.gov/news/articles/2026-09-23 - Arizona Water Banking Authority. Plans of Operation.
https://waterbank.az.gov/plans-reports/plan-operation - Arizona Department of Water Resources. Arizona Intrastate Process for New Intentionally Created Surplus Projects, 2027–2028.
https://www.azwater.gov/arizona-intrastate-process-new-ics-projects-2027-2028 - City of Phoenix Water Services Department. Water Conservation and Drought Management.
https://www.phoenix.gov/newsroom/water-services-news/phoenix-prepared-as-federal-framework-outlines-potential-cuts-to.html - City of Phoenix Water Services Department. Water Services. Information on municipal water supplies, infrastructure, and drought preparation.
https://www.phoenix.gov/waterservices - Axios Phoenix. Mesa’s Water Plan Explained. October 5, 2026. Covers Mesa’s Colorado River dependence, wastewater reuse, advanced water purification, and possible cooperation with Phoenix on the 91st Avenue treatment facility.
https://www.axios.com/local/mesa/2026/10/05/mesa-s-water-plan-explained - Imperial Irrigation District. Deficit Irrigation Program. Information on agricultural conservation and compensation.
https://www.iid.com/water/water-conservation/deficit-irrigation-program - Imperial Irrigation District. Response to the 2027–2028 Colorado River Operating Guidelines. August 21, 2026.
https://www.iid.com/Home/Components/News/News/1556/30?locale=es&npage=8 - Coachella Valley Water District. Colorado River Water Conservation Program. Information on the 2027–2028 agricultural conservation program.
https://www.cvwd.org/580/Colorado-River-Water-Conservation-Progra - Metropolitan Water District of Southern California. Metropolitan Partners with Federal Government to Help Water Levels in Historically Low Lake Mead. July 14, 2026.
https://www-admin.mwdh2o.com/press-releases/metropolitan-partners-with-federal-government-to-help-water-levels-in-historic-low-lake-mead/ - Metropolitan Water District of Southern California. Colorado River Sustainability and Conservation.
https://www-admin.mwdh2o.com/planning-for-tomorrow/securing-our-imported-supplies/colorado-river/ - Nevada Legislature. Conservation of Colorado River Water Act. Statutory provisions governing nonfunctional turf restrictions.
https://www.leg.state.nv.us/SpecialActs/66-Water_ConservationColoradoRiverAct.html - Southern Nevada Water Authority. Conservation Initiatives. Information on grass replacement, water-use reductions, and conservation programs.
https://www.snwa.com/water-resources/conservation-initiatives/index.html - Southern Nevada Water Authority. 2026 Water Resource Plan. Information on water banking, stored supplies, and long-term water management.
https://www.snwa.com/water-resources/water-resource-plan/index.html - Office of Nevada Governor Joe Lombardo. Nevada Files Lawsuit Against Department of the Interior Over Colorado River Operations Record of Decision. August 2026.
https://www.gov.nv.gov/press-releases/nevada-files-lawsuit-against-department-of-the-interior-over-colorado-river-operations-record-of-decision/ - Arizona Department of Water Resources. Lower Division States’ Proposal for Short-Term Operations of the Colorado River. May 1, 2026.
https://www.azwater.gov/sites/default/files/2026-05/2026.05.01%20LB2YearPlanFINAL.pdf
