WSP07735

• File Number: 8282.600.10.A
• Description: Colorado River Annual Operating Plans
• Basin: Colorado Mainstem
• Date: 1/1/1998
• Author: CWCB
• Title: 1999 Annual Operating Plan ‎(AOP)‎
• Water Supply Pro - Doc Type: Data

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tube will likely take place in the next few weeks,

Open forum discussions on Flaming Gorge operations have been taking place at meetings of the
"Flaming Gorge Working Group". The next Working Group meeting is scheduled for September
24 at 7 pm in Vernal, Ut. For more information on the Working Group, contact Ed Vidmar at
801-379-1000.

ASPINALL - May unregulated inflow into Blue Mesa was 189,200 acre-feet or about 88 percent
of average. The June I inflow forecast for April through July runoff is for 600,000 area-feet into
Blue Meas Reservoir. Currently the inflow rate into Blue Mesa Reservoir is averaging about
3,000 cfs. The snowpack for the Gunnison River basin is at 78 percent of normal, while the
precipitation for May was only 25 percent of average. These conditions have resulted in a lower
than anticipated runoff so far this season. Blue Mesa's current elevation is 7492,95 feet with a
storage content of 604,000 acre-feet. The reservoir water surface elevation is raising between 0.4
to 0.5 feet per day.

Releases from Crystal Darn peaked at 4,000 cfs on May 23, Maximum flow rates below the
Gunnison Diversion Tunnel reached 3,200 cfs during this same time period. Current releases at
Crystal are set at 1,900 cfs, Inflows to the Aspinall reservoir system reached a seasonal peak on
June 3. 1998 when the unregulated inflow was 7,000 cfs. Depending on the runoff and forecasts.
the current release at Crystal should remain fairly constant at 1,900 cfs for the summer season,
The Gunnison Diversion Tunnel is currently diverting 1,000 cfs from the river resulting in a river
flow of 900 cfs through the Black Canyon of the Gunnison,

Additional changes to these operations may occur as needed following the issuance of updated
runoff forecasts by the National Weather Service.

The next meeting of the" Aspinall Unit Working Group"7will be held on August 20, 1998 at
l2:30 pm at Blue Mesa Reservoir's Elk Creek Visitors Center. These meetings are open forum
discussions on the Aspinall Unit operations with many interested groups participating. Anyone
needing further information about these meetings should contact Ed Wamer in the Grand
Junction Area Office at [phone].

NA VAJO - May unregulated inflow into Navajo Reservoir was about 285,000 acre-feet or
approximately 102 percent of average, The current reservoir inflow is about 2.300 cfs and the
water surface elevation is at 6068.41 feet which corresponds to a reservoir content of about
1,459,000 acre-feet. Reservoir releases are currently at 5,000 cfs. This release is scheduled to be
reduced starting today. June 10, down to 4,000 cfs and then to 3,000 cfs on June I I. Future
reductions of 1.000 cfs will be made again on June 15, and June 16, then a final reduction of 400
cfs on June l7, when the total release from Navajo Dam will be 600 cfs, This base flow of 600
cfs will then be held through the summer and fall months.

The June I forecast for April through July inflow volumes into Navajo Reservoir was for
650,000 acre-feet, or about 84 percent of average. May precipitation was only 45 percent of
normal and the current snowpack is also at 45 percent of normal for the San Juan Basin,