WSP00896

• File Number: 8282.600.10
• Description: Colorado River Operating Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1984
• Author: USDOI/BOR
• Title: Operation of the Colorado River Basin 1984 Projected Operations 1985
• Water Supply Pro - Doc Type: Publication

Upper Belsln Reservoirs
Fontenelle Reservoir
(Green River)

Water Year 1984

The water year 1984 plan of operation for
Fontanelle Reservoir was to maintain the
wafer surface elevation no higher than
6,482 feet. This operating restriction was
imposed in response to evidence of
increased seepage observed along the left
abutment of the dam in 1982 and
preliminary geologic investigations
conducted during 1983.-

The forecast of April through July runoff
into Fontanelle Reservoir was 138 percent
of normal on January 6, 1984, and
gradually declined to 95 percent of normal
by AprilS. 1984. The elevation of
Fontanelle Reservoir was maintained near
6,482 feet until May 1984, when it was
gradually lowered to just below the
minimum power pool to an elevation of
6,473.7 on May 30, 1984. in anticipation of
high spring flows. The reservoir was
allowed to slowly rise to a peak elevation
of 6,484.9 feel on July 26. 1984. A
maximum release from Fontenelle Dam of
7,560 cfs occurred on May 27. 1964. as
inflow to the reservoir rapidly increased.
The peak inflow occurred on June 2, 1984,
at nearly 9.000 cfs.

The actual April through July runoff into
Fontanelle Reservoir was 972,000 acre-fee1
which was 111 percen1 of normal. Inflow
for the entire water year 1984 was
1.581.0c0 acre-feet or 131 percent of
_normal. _The .total release- from Fontenelle
Dam for water year 1964 was 1.562.000
acre-feet of which 636.000 ocre-fee1
bypassed the powerplon1.

Water Year 1985

The proiected pion of operation for water
year 1985 is essentially the some as for
water year 1984. The reservoir will be
operated between the minimum powerpool
elevation of 6,475 feet and elevation 6.482
feet for the entire water year. The
reservoir will be gradually drawn down to
elevation 6.475 feet just prior to high spring
flows and will then be allowed to rise to

6

Fonlenelle Dom and R8'servoir.

elevation 6.482 feet during the peak of the
spring runoff. The reservoir will be
maintained near this elevation for the
remainder of the water year. The
maximum. release from Fontenelle will be
dependent upon the magnitude of runoff.
The reasonable maximum inflow would
probably produce a maximum discharge of
9.000 cfs. while an average runoff would
produce about a 6.000 cfs release.
Releases would not exceed 4.500 cfs with 0
reasonable minimum inflow.

A Saiety-oi-Dams Modiiication Report is
currently being prepared for the repair of
Fontenelle Dam and is scheduled for
.completion-in-November- 1985.- This report
will evaluate all of the feasible repair
alternatives and their associated costs
which are required for any Congressional
approval oi major funding. In the interim,
a contract is scheduled for award in April
1985 to construct test sections to confirm
the feasibility of a concrete core wall
repair. The State of Wyoming has
indicated an intent to cooperate with the
Bureau of Reclamation in the repair of
Fontenelle Dam with associated cost
sharing. Meetings to negotiate a cost~
shoring agreement with the State of
Wyoming are currently scheduled to begin
in January 1985.

Fontenelle Active Storage"

Chart 1

Reservoir

Acre-Feet

EI. (Ft.)

Maximum Storage
Rated Head
Minimum Power
Surface Areo (Full)
Reservoir Length
(Full)
Powerplont
Number of Units
Total Capoc ity

344.834 65.06
233.789 6491
194.962 6485
8,058 Acres

18 Miles

1
10.000 Kilowatts

"eo.s nOI include !Ib3 ocr..I'" 01 d-.od Iloro~ below 6.406 I..,.