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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DESCRIPTION OF THE COLORADO-BIG THOMPSON PROJECT

The Colorado-Big Thompson Project is one of the la...gest and most complex
natural ...esou...ce developments unde...taken by the Bureau of Reclamation.
It consists of ove... 100 st...uctures integrated into a transmountain water
d i ve...s ion system through wh i ch mu It i P 1 e benefi ts are p...ov i ded to the
people.

The Project spreads over app...oximately 250 miles in the State of
Colorado. It stores, regulates, and diver-ts wate... f...om the Colo...ado
River on the western slope of the Rocky Mountains. It p...ovides
supplemental water for ir...igation of about 720,000 acres of land,
municipal and industrial use, Iiydroelectr-ic powe..., and water-oriented
...ecreation opportunities.

Majo... features of the project include dams,
powerplants, pumping plants, pipelines, tunnels,
substations, and othe'" associated st...uctures (table

dikes, reservoirs,
t...ansmission lines,
I, exhibits 1 and 2).

The P...oject diverts approximately 260,UOO ac...e-feet of wate... annually
(310,OUU acre-feet maximum) from the Colorado Rive... headwaters on the
western slope to the Big Thompson River, a South Platte Rive... t...ibuta...y
on the easte...n slope, for distribution to project lands and communities.
The Northe...n Colorado Water Conservancy Dist...ict apportions the wate...
used for i......igation to more than 120 ditches and 60 reservoi...s. Eleven
communities receive municipal and indust...ial water f...om the Project.
Elect...ic power p...oduced by six powerplants is ma...keted by the Weste...n
Division of the Pick-Sloan Missouri Basin Program.

The western slope collection system traps runoff from the high mountains
and stores, regulates, and conveys the wate... to the Alva B. Adams Tunnel
for diversion unde... the Continental Divide.

To assure irrigation and power gene...ation unde... p...io... ...ights on the
Colorado River, G...een Mountain Reservoi... was const...ucted on the Blue
River. Spring runoff is stored in this rese...voir and later released to
meet the requirements of the Colorado River, and to allow diversion of
wate... by the Project throughout the year.

Irrigation systems on the Colo...ado River, above the Blue Rive...
confluence, were improved to enable continued use of existing rights.
Releases are made f...om Lake Granby to maintain the Colorado River as a
live fishing stream.

The principal storage features are Lake Granby, Grand Lake, and Shadow
Mountain Rese...voi... located on the Colorado River nea... Granby, and Willow
C...eek, a tributa...y below Lake Granby. Willow Creek Pumping Plant lifts
the water 175 feet, wh i ch then flows by grav i ty v i a the Will ow Creek
Feeder Canal to Lake Granby.

Granby Pumping Plant lifts the water 125 feet f...om Lake G...anby to Granby
Pump Cana 1. The can a 1 conveys the wate... 1. 8 mi 1 es to Shadow Mounta i n
Lake, which also intercepts North Fork nows of the Colorado River.
Shadow Mountain' Lake connects with G...and Lake to make a single body
of water from which diversions flow to the Alva B. Adams Tunnel to begin
the journey to the easte...n slope.

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