Bureau of Reclamation Banner, Upper Colorado Region

Navajo Reservoir from the air

 

Navajo Reservoir –Reclamation is currently releasing 350 cfs. 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 6043.4 ft of pool elevation and 1,150,403 acre-ft of storage by the end of March, which was 88% of average for the end of the month. Modified unregulated inflow into Navajo was 89,891 af, which was 97% of average for the month. Calculated evaporation for the month was 1,384 acre-ft.  The release remained 350 cfs throughout the month of March.  Navajo Reservoir recorded 0.99 inches of liquid precipitation (82% of average). 

As of April 6th, the release at Navajo (as measured at the USGS at Archuleta gage) was 373 cfs, and the observed inflow is 1,361 cfs. The reservoir elevation is 6044.35 ft and the content is 1,160,679 acre-ft, or 68% full (48% of Active).  The San Juan River at Four Corners USGS gage is at 824 cfs, and the Animas River at Farmington USGS gage is at 537 cfs.  Snotel sites above Navajo are showing 8.6 inches of SWE (47% of median on this date). Runoff appears to be 4 to 6 weeks early due to the unseasonably warm temperatures.

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 April at Navajo is 110,000 acre-ft (65% of average), for May is 126,000 acre-ft (45% of average), and for June is 63,000 acre-ft (28% of average).  The April-July modified unregulated inflow forecasts are as follows:


Min Probable: 225,000 acre-ft (31% of average, an increase of 5,000 af from Mid-March)
Most Probable: 310,000 acre-ft (42% of average, a decrease of 90,000 af from Mid-March)
Max Probable: 490,000 acre-ft (66% of average, a decrease of 60,000 af from Mid-March)

Under all three forecast probabilities, no spring peak release is expected in 2015.  The most probable forecast shows the reservoir will reach a minimum overwinter storage level of 6042 ft (1,134,700 af) in winter of 2016.  

The last public operations meeting was held January 20th at the Farmington Civic Center. The next operations meeting is scheduled for Tuesday, April 28th 2015. To view minutes from the last Navajo Operations Meeting, click on: Meeting Notes.

Updated April 9th, 2015
Susan Behery

Email comments/inquires to: ResourceMgr@usbr.gov