The U.S. Department of the Interior released more details on Tuesday about how it plans to address the water shortage in the Colorado River Basin.

New Mexico is one of seven states that relies on the Colorado River and its tributaries.

The draft supplemental Environmental Impact Statement that the federal government released this week includes analysis of alternatives and measures that could be used to address potential water shortages if actions are taken to protect the operations at Glen Canyon and Hoover Dam, including the system integrity of the two reservoirs. The Glen Canyon Dam is located at Lake Powell while the Hoover Dam is located at Lake Mead.

“Drought conditions in the Colorado River Basin have been two decades in the making. To meet this moment, we must continue to work together, through a commitment to protecting the river, leading with science and a shared understanding that unprecedented conditions require new solutions,” Bureau of Reclamation Commissioner Camille Calimlim Touton said in a press release. “The draft released today is the product of ongoing engagement with the Basin states and water commissioners, the 30 Basin Tribes, water managers, farmers and irrigators, municipalities and other stakeholders. We look forward to continued work with our partners in this critical moment.”

The draft supplemental Environmental Impact Statement is more than 450 pages long, not including appendices.

It comes as the Bureau of Reclamation is looking to revise the 2007 interim guidelines for the operations of Glen Canyon and Hoover dams. These new guidelines would go into place for the 2024 operating year and would address the potential for continued low runoff from snowpack in the Colorado River Basin this coming winter and through 2027.

The Bureau of Reclamation has taken various measures since 2007 to try to address dwindling reservoir levels.

Last year, the Bureau announced two separate actions to help increase the water levels in Lake Powell by nearly 1 million acre-feet. That involved releasing about 500,000 acre-feet of water from Flaming Gorge Reservoir and reducing the amount of water released from Lake Powell.

The Colorado River Basin states created conservation and efficiency programs last fall to address the drought crisis. For Upper Basin states like New Mexico, these plans primarily focused on voluntary conservation measures.

Despite those efforts, water levels in the two reservoirs continued to decline. Lake Powell reached historic lows in March.

However, this winter’s snowpack brought some reprieve, with both Lake Powell and Lake Mead seeing rising levels as the spring runoff increases river flows.

But that could be a short-lived win should the 2023-2024 winter season result in less snowpack or less runoff.

Climate change has led to increased temperatures, meaning that more winter precipitation is falling as rain and more runoff is evaporating before it reaches the rivers.

“Absent a meaningful and unexpected change in hydrologic conditions and trends, water use patterns, or both, Colorado River reservoirs will continue to decline to critically low elevations, threatening essential water supplies across seven states in the United States and two states in Mexico,” the draft supplemental Environmental Impact Statement reads. “It is foreseeable that without appropriate responsive actions and under a continuation of poor hydrologic trends, major Colorado River reservoirs could continue to decline to ‘dead pool’ in the coming years.”

Dead pool refers to a water level so low that the Bureau of Reclamation cannot control the flow in and out of the reservoir and hydropower cannot be produced. This could have both economic and environmental consequences, including reducing the amount of electricity that is available for utilities.

The document released this week includes several alternatives, but does not name a preferred alternative.

“The Department may select different parts of any of the alternatives to best meet the purpose and need. The action alternatives provide operational tools for continued low-flow conditions in light of the fact that current operating guidelines provide insufficient protection against reservoirs declining to critically low elevations,” the document states.

As with all environmental impact statements, the federal agencies reviewed the possibility of taking no action and continuing with measures already in place, including the 2007 interim guidelines.

The federal agencies will not prioritize filling one reservoir over the other, nor will they undertake decommissioning the Glen Canyon Dam. Nor are the federal agencies going to operate the Glen Canyon Dam as a “run of the river” facility, which would allow the natural flow of water through Glen Canyon. The federal agencies also dismissed recommendations from six states including New Mexico that Reclamation “consider an alternative that apportions among all contractors reductions to account for water evaporation, seepage, and system losses.”

The federal agencies also chose not to analyze suggestions for importing water into the Colorado River system from sources like the Pacific Ocean.

New Mexico, being in the Upper Basin, will face less impacts from the proposed plans than states like Arizona, California and Nevada.

That is because the plans focus mainly on how much water is released from the two reservoirs, which are both located downstream from New Mexico’s supply of Colorado River water.

New Mexico, and other Upper Basin states, are required to allow a certain amount of water to reach Lake Powell.

There are reservoirs in the Upper Basin states, including Navajo Lake in northwest New Mexico, that could be used to release water to help maintain the water levels in Lake Powell. Additional releases from those facilities are considered under alternative two, which “marginally increases the water supply to Lake Powell through releases of water from the Upper Basin reservoirs.”

In addition, alternative two looks at changes to operations at Lake Powell and Lake Mead.

Action alternative one focuses on modifying releases from Lake Powell and Lake Mead.

“The Colorado River Basin provides water for more than 40 million Americans. It fuels hydropower resources in eight states, supports agriculture and agricultural communities across the West, and is a crucial resource for 30 Tribal Nations. Failure is not an option,” Deputy Secretary of the Interior Tommy Beaudreau said in a press release.

Comments are being accepted for 45 days and a record of decision is expected this summer.