Colorado River shortage leads to major water cuts in Arizona

Arizona will have to reduce its Colorado River water usage by 592,000 acre-feet next year, or 21% of its total allotment, the U.S. Bureau of Reclamation announced Tuesday.

The big picture: The bureau declared that the Colorado River basin will be in a Tier 2 shortage starting in 2023, meaning Lake Mead's water level will fall below 1,050 feet.

• A 2019 Drought Contingency Plan (DCP) triggers automatic cuts for different tiers.
• Lake Mead's drop is the result of an ongoing megadrought that's persisted for 22 years.
• Nevada and Mexico will face cuts as well.

Why it's important: The Central Arizona Project (CAP), which transports water from the Colorado River, operates on a priority system that dictates who takes cuts based on various shortage levels from the DCP.

• Under the first round of Tier 2 cuts, the Gila River Indian Community, Tohono O'odham Nation and some cities, including Phoenix, will lose CAP water.
• The majority of CAP water is used for agriculture.
• If Lake Mead drops below 1,045 feet, a second round of Tier 2 cuts will be triggered, leading to a loss of about another 50,000 acre-feet in Arizona.

Yes, but: Numerous cities in the Valley have already begun implementing their drought plans, with municipal governments imposing cutbacks on themselves in some cases.

What they're saying: "We're going to be continuing to work with the partners in the states to develop as many additional conservation agreements as possible," Bureau of Reclamation Commissioner Camille Touton said during Tuesday's press briefing.

Flashback: Touton told the U.S. Senate Committee on Energy and Natural Resources in June that the seven Colorado River basin states would need to conserve an additional 2 million to 4 million acre-feet to cope with the drought.

• The states were unable to reach an agreement on cuts prior to the bureau's release of this month's study on Colorado River projections for the next two years.

Context: Some water officials and experts in Arizona were frustrated that the bureau announced no plans regarding the water that Touton said needed to be conserved in June.

• Arizona Department of Water Resources director Tom Buschatzke said Tuesday afternoon that the Colorado River basin states need the threat of federal action to help them reach a conservation deal.
• "We had an expectation in Arizona and were working the day after June 14 toward an outcome in which the reductions would be enforceable," Buschatzke said, referring to the bureau's announcement that up to 4 million additional acre-feet must be conserved.

Editor's note: This story has been updated to show Tuesday's Tier 2 cuts will not affect Tucson.