Western Colorado Area Office
Colorado River Storage Project
Navajo Unit Operation Meeting
April 23, 2013
Next Meeting: August 27, 2013 at Farmington Civic Center
This meeting was held in Farmington, New Mexico at the Civic Center. The meeting minutes, as mailed, as well as the meeting handouts are available in the archives. Meeting attendance is shown on the archived minutes.
The purpose of these meetings, held annually in January, April, and August, is to gather input for determining upcoming operations for Navajo Reservoir. This input is used in Reclamation’s development of an overall 24-month study for operation of Reclamation projects in the Upper Colorado River Basin, which includes plans for Glen Canyon, Flaming Gorge, Aspinal Unit and Navajo. 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.
Since late October, the release to the river was between 250 and 800 cfs from Navajo Reservoir, which was sufficient to meet target base flows in the critical habitat area. A drier than average fall and spring resulted in a lower-than-average reservoir elevation. The reservoir elevation was the third-lowest in the last thirty years for the end of March.
The reservoir hit a low elevation of 6021 (55% Full) with storage at 925,458 af in late April. The observed inflow for January was 3,344 af (62% of average), for February was 9,917 af (35% of average), and for March was 4,186 af (61% of average). The outlet works release volume for the month of January was 19,735 af (39% of average), for February was 22,391 af (47% of average), and for March was 35,615 af (33% of average). The Navajo Indian Irrigation Project (NIIP) began diverting water from Navajo on March 1st.
Water Year 2013 precipitation was well-below average. Due to low inflow volumes last year and below average precipitation throughout the summer and fall, modeled soil moisture levels entering the water year were well-below average. The average snowpack above Navajo Reservoir, as of April 22, 2013, was at 71 percent of average with a snow water equivalent (SWE) of 12.6 inches. Maximum SWE for the year above Navajo Reservoir was 13.9 inches of SWE (74% of the average peak), reached on March 13th.
The most probable April-July 2013 modified unregulated inflow, based on the mid-April forecast, is 370,000 af, which is 50% of average. The minimum probable and maximum probable April-July inflow forecasts are 250,000 af (34% of average) and 590,000 af (79% of average), respectively.
The Climate Prediction Center indicates precipitation will continue to have a probability of below average precipitation and above average temperatures for the next few months. ENSO models are all showing neutral (El Nino/ La Nina) conditions through summer.
The reservoir elevation on April 22, 2013 was 6,022 feet which corresponds to approximately 933,294 afaf of storage (74% percent of the 30-year average). The reservoir is 55 percent of total capacity. As of April 22, the release to the river is approximately 800 cfs. The release may be decreased if the tributary inflow downstream of the Navajo Reservoir increases enough to be sufficient to maintain the target base flows downstream.An overview of the conditions of nearby reservoirs was presented. Currently, Vallecito Reservoir is approximately 44% full, which is 94% of average for mid-April. Currently, Lemon is approximately 22% of full, which is only 41% of average. Lake Nighthorse is 94% full. No releases are presently scheduled. The project has been transferred to the OM&R Association.
Based on the most and minimum probable inflow forecast, no spring peak release is expected. Under maximum probable conditions, a 1-week spring peak release is possible. Under the mid- April forecast, the reservoir is not projected to have shortages this year, however, the minimum probable forecast shows a minimum pool elevation of only 5 feet over the NIIP intake, where shortage sharing would begin. A minimum release of 250 cfs will be used when possible, however, the release will be increased as necessary throughout the spring and summer to maintain the target base flows in the critical habitat.
Using the current most probable forecast, the San Juan River at Bluff will see below normal flows, peaking at just over 2,000 cfs in late May or early June. This estimate is based on models using comparable historical years, the current Animas forecast, and current forecasted releases from Navajo Reservoir. Flows throughout the San Juan River Basin are anticipated to be much lower than average.
Shortage Sharing Discussion
The possibility of a shortage occurring was summarized. While a shortage is not currently forecasted, the possibility of a forecasted shortage exists if water supply forecasts decrease. A shortage occurs when under Minimum Probable Conditions, the pool elevation at Navajo drops to below 5990 ft at any time during the year. If this possibility exists, several water-saving measures are implemented.
The first water-saving measure was discussed during the August 2012 Operations meeting, and involved invoking the Record of Decision “goal” base release of 350 cfs. This measure is applied under the condition that target base flows are still being met through the critical habitat reach of the San Juan River.
The second water-saving measure is to reduce the base release further to 250 cfs. This is the minimum agreed-upon release documented in the Record of Decision. This measure is applied when the flexibility no longer exists to release anything beyond the absolute minimum required to maintain target base flows through the critical habitat reach. This measure was implemented in January of 2013.
Currently, the first two measures have been implemented, and are enough to prevent a forecasted shortage in the basin. If the forecast continues to decrease, and a shortage forecast becomes imminent, further measures will be undertaken. The third water –saving measure would be a resulting release based on a joint discussion between the Fish and Wildlife Service biologists and Reclamation. The agreement would involve temporarily reducing the goal target base flow through the critical habitat reach in order to save water in the reservoir.
If these measures are not enough to prevent elevations from dropping below 5990 ft at any time of the year, shortage-sharing measures will go into effect. The calculated amount of shortage still unaccounted for by the previous three water-saving measures will be distributed equitably as agreed upon by the endorsing parties.
Work on the Navajo unit buildings and parking lot is scheduled for this spring and summer. Toe drain repair on the right groin will occur later this fall.
Colorado State Parks – The marina is approximately 25% online.
San Juan River Dineh Water Users – The agency is currently looking for grants to convert additional open ditches into pipes for water conservation.
Arizona Public Service (APS) – Agency is prepared for the possibility of a shortage sharing if it occurs.
Navajo Agricultural Products Industry – Cultivating, irrigation and farming have started.
San Juan River Basin Recovery Implementation Program (SJRBRIP) – The habitat restoration of installing fish passages and a fish weir at Hogback was completed.
Hammond Conservancy District – Diversions for the irrigation season have begun.
Scheduled for 1:00 p.m. on Tuesday, April 27, 2013 at the Civic Center in Farmington, New Mexico (200 West Arrington Street).
Meeting Minutes (Portable Document Format (PDF)): View these minutes as mailed (includes attendance list)
Email comments/inquires to: WestColoAreaOffice@usbr.gov