WSP03460

• File Number: 8441.700
• Description: Colorado Big Thompson Project - Annual Operating Plans
• Basin: South Platte
• Water Division: 1
• Date: 1/1/1989
• Title: Annual Operating Plans - Colorado Big Thompson Project - Water Year 1989-1990
• Water Supply Pro - Doc Type: Report/Study

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through Flatiron Unit 3 fo... testing pu...poses, which p...oduced
7,U49 kilowatt hou...s of energy.

A total of 69,206 acre-feet of water was pumped to Ca...ter Lake du...ing
the wate... year which was 86 percent of ave...age. This required
22,100,000 kilowatt-hou...s of ene...gy.

Ho...setooth Reservoir

Comp 1 eted in 1949, with fou... dams, Horsetooth Reservoi r has a tota 1
const...ucted capacity of 156,700 acre-feet. Inflow of Project water is
f...om Flatiron Rese...voir via the Cha...les Hansen Feeder Canal.

Horsetooth Reservoir sto...age of 70,166 ac...e-feet at the sta...t of water
year 1989 was nea... the 30-yea... no...mal of 71,800 ac...e-feet.

During early Octobe..., most P...oject water b...ought over from the Colo...ado
Rive... was pumped to Carter Lake due to the schedu led pressure tunne 1
wo...k. Maintenance on the 550 ft3/s section of the Charles Hansen Feede...
Canal, during the Octobe... 1 to October 14 period, p...evented t...ansfe... of
wate... to Ho...setooth.

No...mal t...ansfer of water to Ho...setooth Reservoir th...ough the foothills
system of the Project began on October 14 when the 550 ft3/s section
of the Charles Hansen Feede... Canal became available. This operation
continued through mid-September when the 930 ft3/s section of the
Cha...les Hansen Feede... Canal was shut down for the annual slab ...eplacement.
Dille Tunnel was then utilized fo... the remainder of Septembe... to deliver
water to Ho...setooth Reservoi.... Fo... wate... year 1989, the maximum
Horsetooth Rese...voi... storage of 134,131 acre-feet (water surface
elevation 5418.44 feet) was ...eached on April 6. This was 6.66 feet
below the current rest...icted maximum water su...face elevation of
5425.10 feet (146,900 ac...e-feet).

Project water del iveries began on Ap...il 25 and we...e near 225 ft3/s by
the end of the month. May wate... de 1 i veri es from Ho...setooth Rese...voi...
were 461 percent above ave...age due to an extremely dry spring, for a
total of 23,500 acre-feet.

Water deliveries were 121 percent and 137 percent of ave...age in June and
July, at 9,400 acre-feet and 38,500 ac...e-feet, ...espect i ve ly. August
p...oject wate... delive...ies of 30,800 acre-feet we...e below normal at
94 percent of average. September p...oject water deliveries decreased to
55 percent of average. Total seasonal water del ive...ies (October-September)
for 1989 were 26,300 acre-feet above norma 1 at a tot a 1 of
119,500 acre-feet.

The September 30 end-of-wate...-yea... storage totaled 63,778 ac...e-feet
and this was 8,022 acre-feet below the 1959-1985 ave...age. The actual
operations fo... the Colorado-Big Thompson Project for water yea... 1989
are summa...ized in table 3.