WSP04480

• File Number: 8282.600.40
• Description: Colorado River Annual Operating Reports
• Basin: Colorado Mainstem
• Date: 7/1/1997
• Author: USDOI/BOR
• Title: Colorado River Reservoir Operation Status Reports Part 2
• Water Supply Pro - Doc Type: Data

continue throughout the fall and early winter months.

Precipitation in August was 115 percent of normal for the San
Juan River Basin above Bluff. This wetter than expected month
gave a boost to reservoir inflows. Navajo Reservoir actually
gained 24,000 acre-feet of storage during August when normally
the reservoir storage is reduced.

It should be noted that the large EI Nino event that is currently
being observed in the Pacific equatorial regions is predicted to
result in above average precipitation for the southwest this fall
season. Therefore, reservoir operational changes could be made
this fall season to the flow release as stated above.

Anyone needing further information about the daily operations of
Navajo Reservoir should contact Don Fazzan or Rege Leach in the
Durango Office at [phone].

Glen Canyon - Inflows to Lake Powell were 101 percent of normal
in July and are expected to be about 160 percent of normal in
August. Streamflows rapidly receded throughout the basin in July,
but recent precipitation has increased the flow at many sites.

Glen Canyon Dam releases are continuing at 21,000 cfs and will
remain at this level through August 29. Lake Powell inflows are
currently at about 10,000 cfs. The maximum lake level occurred
about mid July when the lake rose to within 5 feet of full
(elevation 3695) and the current level of Lake Powell is about
3691 feet. A low flow release of 8,000 cfs has been scheduled
for the weekend of August 30 through September 1, 1997 to conduct
annual monitoring activities in the Grand Canyon. Releases will
be reduced beginning 10 pm Mountain Daylight Time on Friday
August 29, 1997, ramping down at 1,000 cfs per hour until 8,000
cfs is reached. Flows will remain steady at this level
throughout the Labor Day weekend. Releases will be increased
beginning 6 am Tuesday morning September 2, 1997, ramping up at a
rate of 3,000 cfs per hour until flows return to about 21,000
cfs.

The Colorado River Management Work Group meetings to discuss the
1998 Annual Operating Plan for the entire Colorado River have
concluded with a consultation meeting on July 29, 1997. We
expect the 1998 AOP to be issued by the Secretary of the Interior
by October 1, 1997. Technical subteam meetings are continuing to
evaluate the implications of alternative surplus determination
guidelines. For further information contact Randall Peterson at
[phone] or Jayne Harkins at [phone].