(Last Updated: January 13, 2016)
Navajo 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 6063.8 feet of pool elevation and 1,397,022 acre-feet of storage by the end of December, which was 104% of average for the end of the month. Modified unregulated inflow into Navajo was 22,399 acre-feet, which was 89% of average for the month. Calculated evaporation for the month was 654 acre-ft. The release averaged close to 350 cfs throughout the month.
As of January 6th, the San Juan River at the USGS Archuleta gage was 266 cfs, and the observed inflow is 544 cfs. Note that at very low releases, Archuleta's shift migrates due to sediment and moss issues. The scheduled release is 350 cfs, measured using the gate curves and reservoir elevation head. The reservoir elevation is 6063.81 feet and the content is 1,397,022 acre-ft, or 82% full (71% of Active). The San Juan River at Four Corners USGS gage is at 730 cfs, and the Animas River at Farmington USGS gage is at 343 cfs. Snotel sites above Navajo are showing 11.5 inches of SWE (112% of median on this date).
The most probable modified-unregulated inflow forecast for January at Navajo is 19,000 acre-feet (87% of average), for February is 24,000 acre-feet (79% of average), and for March is 80,000 acre-feet (87% of average). The April-July modified unregulated inflow forecasts are as follows:
Min Probable: 550,000 acre-feet (75% of average)
Most Probable: 770,000 acre-feet (104% of average)
Max Probable: 1,120,000 acre-feet (152% of average)
Please contact the Operations Group via e-mail at ResourceMgr@usbr.gov for additional information.
Last Updated: 2/1/16