Environmental

Steps released to protect Colorado River system water levels

Steps released to protect Colorado River system water levels

Faced with worsening drought across the western U.S., the Department of the Interior announced on August 16 what it said was “urgent action” to improve and protect the long-term sustainability of the Colorado River system.

The announcement included commitments for continued engagement with impacted states and Tribes. And the Bureau of Reclamation released the Colorado River Basin August 2022 24-Month Study, which sets the annual operations for Lake Powell and Lake Mead in 2023 in light of what it said are critically low reservoir conditions.

Prolonged drought and low runoff conditions have led to historically low water levels in Lakes Powell and Mead, both of which supply water for hydroelectric powerhouses.

“The worsening drought crisis impacting the Colorado River Basin is driven by the effects of climate change, including extreme heat and low precipitation. In turn, severe drought conditions exacerbate wildfire risk and ecosystems disruption,” said Deputy Secretary Tommy Beaudreau. “The Biden-Harris administration is taking an all-of-government approach to mitigating the drought, and the Interior Department is committed to using every resource available to conserve water and ensure that irrigators, Tribes and adjoining communities receive adequate assistance and support to build resilient communities and protect our water supplies.”

Downstream releases from Glen Canyon and Hoover dams – which create lakes Powell and Mead – will be reduced again in 2023 due to declining reservoir levels. In the Lower Basin, the reductions represent the second year of additional shortage declarations.

Key determinations from the August 2022 24-Month Study include:

Lake Powell will operate in the Lower Elevation Balancing Tier in water year 2023 (Oct. 1, 2022, through Sept. 30, 2023). The study projects Lake Powell’s Jan. 1, 2023, water surface elevation to be 3,521.84 feet – 178 feet below full pool (3,700 feet) and 32 feet above minimum power pool (3,490 feet). Minimum power pool is the lowest reservoir elevation at which hydroelectric power can be produced. Lake Powell will likely release 7 million acre-feet in water year 2023, with the potential for releases to range from 7 to 9.5 maf during water year 2023, depending on hydrologic conditions, as Lake Powell and Lake Mead balance storage contents.

The department will evaluate hydrologic conditions in April 2023 and limit water year 2023 releases (with a minimum of 7 maf) to protect Lake Powell from declining below 3,525 feet at the end of December 2023.  

Lake Mead will operate in its first-ever Level 2a Shortage Condition in calendar year 2023 (Jan. 1, 2023, through Dec. 31, 2023). The study projects Lake Mead’s Jan. 1, 2023, operating determination elevation to be 1,047.61 feet, which is calculated by taking Lake Mead’s projected end of calendar year 2022 physical elevation (1,040.78 feet) and adding the 480,000 acre-feet of water held in Lake Powell to Lake Mead’s capacity to maintain operational neutrality. The projected elevation of 1,047.61 feet reflects a Level 2a Shortage Condition, with these required shortage reductions and water savings contribution for Arizona, Nevada and Mexico:

Arizona: 592,000 acre-feet, about 21% of the annual apportionment

Nevada: 25,000 acre-feet, 8% of the annual apportionment

Mexico: 104,000 acre-feet, about 7% of the annual allotment

There is no required water savings contribution for California in 2023 under this operating condition.

In May 2022, drought operations to protect Lake Powell were implemented and Glen Canyon Dam releases were reduced, which together provided about 1 maf of additional water to help protect levels at Lake Powell.

Reclamation said it will begin efforts to modify low reservoir operations at both lakes to be prepared to reduce releases in 2024 to address continued drought and low runoff conditions in the basin.

In recent months, Reclamation has documented the increasing risks that will continue to impact Lake Powell and Lake Mead. Reclamation’s “Protection Volume Analysis” details that, depending on future snowpack and runoff, a range of actions will be needed to stabilize lake elevations from 2023 to 2026. Depending on Lake Powell’s inflow, the additional water or conservation needed ranges from 600,000 acre-feet to 4.2 maf annually.

In June 2022, Bureau of Reclamation Commissioner Camille Calimlim Touton called on water users across the basin to take actions to prevent the reservoirs from falling to critically low elevations that would threaten water deliveries and power production. In addition to undertaking preliminary work to develop the post-2026 strategies and operations (several reservoir and water management decision documents expire at the end of 2026), Reclamation will immediately initiate several administrative actions.

In both basins, Reclamation will invest in system conservation and voluntary agreements and consider other operational actions to establish flexibility in operations at Reclamation facilities.

In addition, in the Upper Basin, Reclamation will:

Take administrative actions needed to authorize reducing Glen Canyon Dam releases below 7 maf per year, if needed, to protect this critical infrastructure.

Accelerate maintenance actions and studies to determine and enhance projected reliability of the use of the river outlet works, or bypass tubes, at Glen Canyon Dam for extended periods.

Support technical studies to ascertain if Glen Canyon Dam can be modified physically to allow water to be pumped or released from below currently identified critical and dead pool elevations.

Continue to work with the basin states, basin Tribes, stakeholders and partners to be prepared to implement additional substantial releases from Upper Basin reservoirs to help enhance reservoir elevations at Lake Powell.

And in the Lower Basin, Reclamation will:

Take administrative actions needed to further define reservoir operations at Lake Mead, including shortage operations at elevations below 1,025 feet to reduce the risk of Lake Mead declining to critically low elevations.

Prioritize and prepare for additional administrative initiatives that would ensure maximum efficient and beneficial use of urban and agricultural water and address evaporation, seepage and other system losses.

Support technical studies to ascertain if Hoover Dam can be modified physically to allow water to be pumped/released from elevations below currently identified dead pool elevations.

“Every sector in every state has a responsibility to ensure that water is used with maximum efficiency. In order to avoid a catastrophic collapse of the Colorado River System and a future of uncertainty and conflict, water use in the Basin must be reduced,” said Assistant Secretary for Water and Science Tanya Trujillo. “The Interior Department is employing prompt and responsive actions and investments to ensure the entire Colorado River Basin can function and support all who rely on it.”