Navajo Reservoir

Navajo Dam

Current Status

Navajo Reservoir – The current (September 6th) release rate from Navajo Dam is 750 cfs and the observed inflow to Navajo Reservoir is 73 cfs.  The Navajo Indian Irrigation Project (NIIP) is diverting 734 cfs.  The reservoir elevation is 6026.7 feet which corresponds to a live storage of 0.976 maf (57 percent of live storage capacity).  This elevation also corresponds to an active storage of 0.314 maf (30 percent of active storage capacity).  The river flow measured at the San Juan River at Four Corners USGS gage is 560 cfs.  River flow at the Animas River at Farmington USGS gage is at 16 cfs.  Releases from Navajo Dam are made for the authorized purposes of the Navajo Unit, and pursuant to the 2006 Record of Decision, 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 (SJRIP) 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.


Preliminary modified-unregulated inflow into Navajo (inflow adjusted for upstream change in storage, reservoir evaporation and exportation from the basin) in August was -6,552 af.  For the month of August, this value falls within the bottom 5 percent of all historical modified-unregulated inflows to Navajo Reservoir.  In dry years during irrigation season, the modified-unregulated inflow to Navajo Reservoir may be calculated as negative values when observed inflow values to Navajo Reservoir are small and concurrent change in storage values at Vallecito Reservoir are large as is the case that has occurred this summer. The modified-unregulated inflow during the April through July period was 156,959 af, which was 21 percent of average.


Forecast modified-unregulated inflow to Navajo over the next three months (September, October, and November) are projected to be: 5,000 af (12 percent of average), 10,000 af (21 percent of average), and 10,000 af (30 percent of average), respectively.  


Releases for the fall and winter will be made to maintain the minimum target baseflow in the critical habitat reach and will decrease as irrigation in the basin decreases.  When conditions allow, the release will be reduced to as low as the minimum release of 250 cfs, so long as the target baseflow downstream is still met. 

Reclamation conducts Public Operations Meetings three times per year to gather input for determining upcoming operations for Navajo Reservoir. Input from individuals, organizations, and agencies along with other factors such as weather, water rights, endangered species requirements, flood control, hydro power, recreation, fish and wildlife management, and reservoir levels, will be considered in the development of these reservoir operation plans. In addition, the meetings are used to coordinate activities and exchange information among agencies, water users, and other interested parties concerning the San Juan River and Navajo Reservoir. The next Navajo Public Operations Coordination Meeting is scheduled for Tuesday, January 29th, 2018, at 1:00 p.m. at the Farmington Civic Center, Farmington, NM.


Susan Behery
sbehery@usbr.gov
September 6th, 2018

 

 

 

 

Additional Information

Last Updated: 9/7/18