Bureau of Reclamation Banner, Upper Colorado Region

Navajo Reservoir from the air

 

Navajo Reservoir –Reclamation has been releasing 650 cfs from Navajo Reservoir since September 2nd, 2014. Releases are made for the authorized purposes of the Navajo Unit, and to attempt to maintain a target base flow through the endangered fish critical habitat reach of the San Juan River (Farmington to Lake Powell). The San Juan River Basin Recovery Implementation Program recommends a target base flow of between 500 cfs and 1,000 cfs through the critical habitat area.  The target base flow is calculated as the weekly average of gaged flows throughout the critical habitat area.


Navajo was at 6037.7 ft of pool elevation and 1,088,371 acre-ft of storage by the end of August, which was 78% of average for the end of the month. Observed inflow into Navajo was 33,660 af, (modified-unregulated inflow volume of 15,800 af) which was 54% of average for August. Calculated evaporation for the month was 3,052 acre-ft.  Navajo's releases varied between 550 cfs and 750cfs, taking advantage of rainstorms when possible to save water. Over the month, the released averaged out at 700 cfs.  Navajo Reservoir recorded 1.40 inches of liquid precipitation (74% of average). NIIP diverted a total of 36,695 and has diverted a total of 176,910 af since the beginning of the year. Total April-July modified-unregulated inflow into Navajo was 428,086 af (58% of average).

As of September 2nd, the release at Navajo (as measured at the USGS at Archuleta gage) was 558 cfs, and the observed inflow was 351 cfs.  NIIP was diverting 606 cfs.  The reservoir elevation is 6037.40 ft and the content is 1,084,973 acre-ft, or 64% full (41% of Active).  The San Juan River at Four Corners USGS gage is at 484 cfs, and the Animas River at Farmington USGS gage is at 173 cfs.  The release at Navajo was increased to 650cfs at 11pm on September 2nd.

To view the most current reservoir elevation, content, inflow and release, click on: Navajo Reservoir Data. For up-to-date release information and notices, click on Navajo webpage Notices.

The most probable modified-unregulated inflow forecast for September at Navajo is 17,000 acre-ft (39% of average), for October is 25,000 acre-ft (53% of average), and for November is 25,000 acre-ft (75% of average). The reservoir is forecast to reach a minimum overwinter storage level of 6035 ft/1,056,731 af under theMost Probable forecast.

Reclamation and SJRIP agreed to forego a spring peak release for 2014 in the interests of recovering the reservoir and reducing the risk of a shortage. The release will continue to be that which is required to maintain the target base flows downstream. The last public operations meeting was held on August 26th at the Farmington Civic Center. The next operations meeting is scheduled for Tuesday, January 20th 2015. To view minutes from the last Navajo Operations Meeting, click on: Meeting Notes.

Updated September 17th, 2014
Susan Behery

Email comments/inquires to: ResourceMgr@usbr.gov