- A Tier 1 Shortage Condition remains in effect for Lake Mead, cutting water deliveries to Arizona and Nevada.
- Both Arizona and California are forecast to exceed their approved water use totals for 2026.
- Conservation banking by major water agencies is helping offset some of the pressure on the river system.
Friday, July 17, 2026 — A federal forecast released July 14, 2026 by the Bureau of Reclamation
shows the lower Colorado River system operating under a Tier 1 Shortage Condition for 2026, a designation that triggers mandatory cuts to water deliveries for two of the three states that draw from the river below Lake Mead.
The Bureau of Reclamation is the federal agency responsible for managing water from the Colorado River. Its Lower Colorado Basin office tracks how much water each state, tribe, and irrigation district is taking from the river and compares that against what each entity is legally allowed to use.
The July 14 forecast is a snapshot of where things stand roughly halfway through the calendar year, and the numbers tell a story worth paying attention to.
What a Tier 1 Shortage Actually Means.
Under rules adopted in 2007 and reinforced through subsequent drought agreements, Lake Mead’s water level determines how much each state must cut back. When the lake drops below certain thresholds, a “shortage” is declared, and water deliveries are reduced accordingly.
In 2026, that shortage sits at the first and lowest tier, known as Tier 1. That still translates into real cuts. Arizona must absorb a reduction of 320,000 acre-feet from its basic water allocation. An acre-foot is roughly the amount of water a family of four uses in a year. Arizona must also contribute an additional 192,000 acre-feet in what are called Drought Contingency Plan contributions, a separate set of agreements designed to keep Lake Mead from dropping even further.
Nevada faces smaller cuts, losing 13,000 acre-feet from its allocation, plus an 8,000 acre-foot Drought Contingency Plan contribution.
California is not subject to shortage reductions under this tier, though it faces its own pressures, as detailed below.
Arizona and California Both on Track to Exceed Approved Limits.
One of the more notable findings in the July 14 forecast is that two of the three lower basin states are projected to finish the year above their approved water use levels.
Arizona is forecast to use approximately 2,064,035 acre-feet by year’s end, compared to its approved total of 2,032,398 acre-feet. That puts the state on track for an overrun of roughly 31,637 acre-feet.
California is forecast to use approximately 3,986,254 acre-feet, versus an approved total of 3,951,144 acre-feet, an overrun of about 35,110 acre-feet.
Nevada, by contrast, is forecast to land almost exactly at its approved use of 204,196 acre-feet, with no projected excess.
It is important to note that these are forecasts, not final figures. The Bureau of Reclamation builds these projections using data from 84 daily reporting stations across the lower basin. Numbers can and do shift as new readings come in and as water managers adjust their schedules.
Two Users Drawing Extra Attention.
Within those state totals, a few individual water users stand out.
The Colorado River Indian Tribes, whose reservation straddles the Arizona-California border, are forecast to exceed their estimated water use by approximately 69,277 acre-feet on the Arizona side alone. That is among the largest individual overruns in the forecast.
The Wellton-Mohawk Irrigation and Drainage District, a farming district in far western Arizona near Yuma, is forecast to overrun its approved diversion by approximately 16,739 acre-feet.
On the other side of the ledger, the Imperial Irrigation District in California’s Imperial Valley is forecast to come in slightly under its estimated use, with a projected shortfall of roughly 32,753 acre-feet compared to its target of 2,337,800 acre-feet.
Conservation Banking: A Critical Piece of the Puzzle.
Even as some users inch above their allocations, large water agencies across the region are working to build what are known as Intentionally Created Surplus, or ICS, accounts. These are essentially water savings accounts. An agency conserves water, deposits those savings into a federally tracked account, and can draw on them in future dry years.
The Metropolitan Water District of Southern California has an approved plan to create up to 450,000 acre-feet of what is called Extraordinary Conservation ICS in 2026. The Southern Nevada Water Authority has options to create up to 100,000 acre-feet of the same type.
The total amount of Extraordinary Conservation ICS that Arizona, California, and Nevada can collectively create in 2026 is capped at 625,000 acre-feet under current rules.
The Imperial Irrigation District is targeting the creation of 265,000 acre-feet of System Conservation Water, another form of water savings that benefits the broader river system.
Mexico’s Share: Treaty Obligations Met, With Some Extra.
The river does not stop at the United States-Mexico border. Under a 1944 treaty, the United States is obligated to deliver 1,500,000 acre-feet of water to Mexico each year, with some flexibility built in for drought years.
The July 14 forecast projects that the United States will deliver approximately 1,450,000 acre-feet in satisfaction of that treaty, with an additional 13,168 acre-feet expected in excess of the treaty amount. A separate 137,143 acre-feet is forecast to be bypassed into Mexico under the terms of Minute 242, an agreement addressing salinity issues along the border near Yuma.
When all lower basin deliveries are added together, including water used by the three states, tribal deliveries, and all water flowing to Mexico, the total forecasted demand on the lower Colorado River system for 2026 stands at approximately 7,708,754 acre-feet.
What Comes Next.
The Bureau of Reclamation updates its lower basin forecast regularly throughout the year. The next update will reflect new diversion data and any schedule changes made by water managers. Abrupt shifts in any of the trend lines tracked by the agency typically signal that a water district has changed its diversion schedule or that new real-time readings have altered the projection.
For the millions of people across the desert Southwest who depend on the Colorado River for drinking water, irrigation, and economic activity, the July 14 forecast is a reminder that the river remains under stress and that the rules, agreements, and conservation programs now in place are being tested in real time.
Data in this article is sourced from the Bureau of Reclamation Lower Colorado Basin Consumptive Uses and Losses Forecast, dated July 14, 2026.
