Alva B. Adams Tunnel
Encyclopedia
The Alva B. Adams Tunnel is the principal component of the largest transmountain water project in Colorado--the Colorado-Big Thompson Project
(C-BT). The tunnel transfers water from the western slope of the Colorado River
drainage to users on the eastern Front Range
of Colorado. The tunnel is 13.1 miles (21.1 km) long and has a concrete lined diameter of 9.75 feet (3 m). The tunnel runs in a straight line under the Continental Divide
from west to east and passing under Rocky Mountain National Park
. Construction began on June 15, 1940, but was suspended as a result of World War II from the end of 1942 to August 1943. The tunnel was holed through on March 31, 1944, an event that was broadcast throughout the United States by NBC Radio. The tunnel was posthumously named for its chief advocate, US Senator Alva B. Adams
.
West of the Continental Divide the input of the tunnel is water pumped from Windy Gap Reservoir, Willow Creek Reservoir and other North Fork of the Colorado River
drainages to Lake Granby
. From Lake Granby the water is pumped into Shadow Mountain reservoir and then flows by gravity to Grand Lake (Colorado)
, Colorado's largest natural body of water, from where it pours through the tunnel. Lake Granby is the second largest reservoir in the state of Colorado with a nominal capacity of 470000 acre.ft. Once the water reaches the Front Range
on the eastern side of the Rocky Mountains
it is used to generate electricity as it falls almost half a mile (1 km) through five power plants on its way down the Front Range. To get the power from the Front Range
reservoirs and power plants back to the pumps on the western slope a 5 inches (12.7 cm) diameter water tight nitrogen-filled conduit carrying a 69,000 volt electric power transmission line is mounted on the roof of the tunnel. This power is used to power the pumps on the western side of the tunnel while surplus power is sold. West slope water is stored on the Front Range in Mary's Lake, Lake Estes, Carter Lake (all reservoirs), Flatiron Reservoir, Horsetooth Reservoir
and Boulder Reservoir for power generation or release after the peak snow melt months of May to July have passed.
The tunnel is capable of transporting 550 cuft/s of water. An average annual total of 213000 acre.ft of water are diverted through the tunnel from the west to the east slope per year. The tunnel can flow as much as 1100 acre.ft in one day. The water transferred through the tunnel is considered part of Colorado's Colorado River
water allocation of 3880000 acre.ft per year as agreed to in the Colorado River Compact
.
Entrance 40.247302°N 105.810013°W
Exit 40.346381°N 105.535269°W
Colorado-Big Thompson project
The Colorado-Big Thompson Project is a water diversion project in Colorado designed to collect West Slope mountain water from the headwaters of the Colorado River and divert it to Colorado's Front Range and plains...
(C-BT). The tunnel transfers water from the western slope of the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
drainage to users on the eastern Front Range
Front Range
The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the north-central portion of the U.S. State of Colorado and southeastern portion of the U.S. State of Wyoming. It is the first mountain range encountered moving west along the 40th parallel north across...
of Colorado. The tunnel is 13.1 miles (21.1 km) long and has a concrete lined diameter of 9.75 feet (3 m). The tunnel runs in a straight line under the Continental Divide
Continental Divide
The Continental Divide of the Americas, or merely the Continental Gulf of Division or Great Divide, is the name given to the principal, and largely mountainous, hydrological divide of the Americas that separates the watersheds that drain into the Pacific Ocean from those river systems that drain...
from west to east and passing under Rocky Mountain National Park
Rocky Mountain National Park
Rocky Mountain National Park is a national park located in the north-central region of the U.S. state of Colorado.It features majestic mountain views, a variety of wildlife, varied climates and environments—from wooded forests to mountain tundra—and easy access to back-country trails...
. Construction began on June 15, 1940, but was suspended as a result of World War II from the end of 1942 to August 1943. The tunnel was holed through on March 31, 1944, an event that was broadcast throughout the United States by NBC Radio. The tunnel was posthumously named for its chief advocate, US Senator Alva B. Adams
Alva B. Adams
Alva Blanchard Adams was a Democratic politician who represented Colorado in the United States Senate from 1923 until 1924 and again from 1933 to 1941.-Biography:...
.
West of the Continental Divide the input of the tunnel is water pumped from Windy Gap Reservoir, Willow Creek Reservoir and other North Fork of the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
drainages to Lake Granby
Lake Granby
Lake Granby is the second largest body of water in Colorado. It was created as part of the Colorado-Big Thompson Project and forms a continuous body of water with Shadow Mountain Reservoir and Grand Lake. On its own, Lake Granby contains approximately 40 miles of shoreline. The lake is popular...
. From Lake Granby the water is pumped into Shadow Mountain reservoir and then flows by gravity to Grand Lake (Colorado)
Grand Lake (Colorado)
Grand Lake is Colorado's largest and deepest natural lake, one of the headwaters of the Colorado River in Grand County, Colorado. On its shores is located the eponymous town of Grand Lake. The elevation of the lake surface is 8,367 feet . It is formed by the damming of several streams by a...
, Colorado's largest natural body of water, from where it pours through the tunnel. Lake Granby is the second largest reservoir in the state of Colorado with a nominal capacity of 470000 acre.ft. Once the water reaches the Front Range
Front Range
The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the north-central portion of the U.S. State of Colorado and southeastern portion of the U.S. State of Wyoming. It is the first mountain range encountered moving west along the 40th parallel north across...
on the eastern side of the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
it is used to generate electricity as it falls almost half a mile (1 km) through five power plants on its way down the Front Range. To get the power from the Front Range
Front Range
The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the north-central portion of the U.S. State of Colorado and southeastern portion of the U.S. State of Wyoming. It is the first mountain range encountered moving west along the 40th parallel north across...
reservoirs and power plants back to the pumps on the western slope a 5 inches (12.7 cm) diameter water tight nitrogen-filled conduit carrying a 69,000 volt electric power transmission line is mounted on the roof of the tunnel. This power is used to power the pumps on the western side of the tunnel while surplus power is sold. West slope water is stored on the Front Range in Mary's Lake, Lake Estes, Carter Lake (all reservoirs), Flatiron Reservoir, Horsetooth Reservoir
Horsetooth Reservoir
Horsetooth Reservoir is a large reservoir in southern Larimer County, Colorado just west of the city of Fort Collins, Colorado. The reservoir sits in the foothills above the town on the western side of the Dakota Hogback, which contains the reservoir along its eastern side...
and Boulder Reservoir for power generation or release after the peak snow melt months of May to July have passed.
The tunnel is capable of transporting 550 cuft/s of water. An average annual total of 213000 acre.ft of water are diverted through the tunnel from the west to the east slope per year. The tunnel can flow as much as 1100 acre.ft in one day. The water transferred through the tunnel is considered part of Colorado's Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
water allocation of 3880000 acre.ft per year as agreed to in the Colorado River Compact
Colorado River Compact
The Colorado River Compact is a 1922 agreement among seven U.S. states in the basin of the Colorado River in the American Southwest governing the allocation of the water rights to the river's water among the parties of the interstate compact...
.
Entrance 40.247302°N 105.810013°W
Exit 40.346381°N 105.535269°W