Reclamation’s July 24-Month Study implements contingency operations in the Upper #ColoradoRiver Basin #COriver #aridification #GreenRiver #SanJuanRiver #GunnisonRiver

Here’s the release from the Bureau of Reclamation (Patti Aaron):

The Bureau of Reclamation today released the July 24-Month Study, confirming declining hydrologic conditions for the Colorado River system. To protect Lake Powell’s target elevation, the study incorporates the implementation of drought operations under the Upper Basin Drought Response Operations Agreement (DROA).

The July 2021 Operation Plan for Colorado River System Reservoirs 24-Month Study (July 24-Month Study) shows that the Lake Powell water year 2021 predicted unregulated inflow volume has decreased 2.5 million acre-feet in the six-month period between January and July 2021. The current forecast for WY2021 is 3.23 maf (30% of average).

In addition, 5-year projections released by Reclamation last week predicted a 79% chance that Lake Powell would fall below the DROA target elevation of 3,525 feet within the next year. That target elevation provides a 35 vertical-foot buffer designed to minimize the risk of dropping below the minimum power pool elevation of 3,490 feet, and balances the need to protect the infrastructure at Glen Canyon Dam and meet current operational obligations to the Lower Basin States of Arizona, California and Nevada.

Consistent with DROA provisions to protect Lake Powell’s target elevation, the July 24-Month Study includes adjusted releases from the upstream initial units of the Colorado River Storage Project Act to deliver an additional 181 thousand-acre feet of water to Lake Powell by the end of December 2021. The additional releases are anticipated to be implemented on the following schedule:

The releases detailed above are in addition to the already established releases determined by operational plans for each of the identified facilities. The additional delivery of 181 kaf is expected to raise Lake Powell’s elevation by approximately three feet. The additional releases from the upstream initial units do not change the annual volume of water released from Lake Powell to Lake Mead in WY2021, as those volumes are determined by the 2007 Interim Guidelines.

Reclamation publishes a 24-Month Study for Colorado River System reservoirs each month. The August 24-Month Study will set the operating conditions for Lake Mead and Lake Powell for the upcoming year. Reclamation will also release an update to the 5-year projections in early September.

Reclamation and the Colorado River Basin states continue to work together cooperatively to closely monitor projections and conditions and are prepared to take additional measures in accordance with the DROA.

Reclamation remains committed to reducing the collective risk of both Lake Powell and Lake Mead falling to critical elevations and will continue to work with entities in the Colorado River Basin to ensure that both facilities continue to function as authorized to meet the natural, municipal and agricultural needs of the basin.

To view the July and prior 24-month studies, visit http://www.usbr.gov/uc/water/crsp/studies.