Navajo Reservoir –Navajo is currently releasing 650 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 6065.5 ft of pool elevation and 1,419,656 acre-ft of storage by the end of August, which was 102% of average for the end of the month. Modified unregulated inflow into Navajo was 15,257 af, which was 34% of average for the month. Calculated evaporation for the month was 3,818 acre-ft. NIIP diverted a total of 32,885 acre-ft. The release averaged close to 680 cfs throughout the month. Precipitation at the dam totaled 1.09 inches (58% of average). The April-July inflow total this year was 618,760 af (84% of average).
As of September 2nd, the release at Navajo (as measured at the USGS at Archuleta gage) was 600 cfs, and the observed inflow is 983 cfs. NIIP is diverting 463 cfs. The reservoir elevation is 6065.5 ft and the content is 1,419,389 acre-ft, or 83% full (73% of Active). The San Juan River at Four Corners USGS gage is at 725 cfs, and the Animas River at Farmington USGS gage is at 189 cfs.
The most probable modified-unregulated inflow forecast for September at Navajo is 20,000 acre-ft (46% of average), for October is 30,000 acre-ft (64% of average), and for November is 29,000 acre-ft (87% of average).
The most probable forecast shows the reservoir will end the water year (Sept 30th) near 6063 ft (1,385,000 af), and reach a minimum overwinter storage level near 6058 ft (1,324,000 af) in February of 2016.
Updated September 9th, 2015
Email comments/inquires to: ResourceMgr@usbr.gov