History of Water

Grand County has a rich water history and some of the most interesting water attractions in the state. These attractions have helped to shape the growth and development of Colorado and the Front Range.

Alva B. Adams Tunnel

• Part of the Colorado Big Thompson Project
• Tunnel named for US senator from Colorado who played a large role in convincing Congress to fund and construct the Colorado Big Thompson Project.
• Construction began on June 23, 1940 southwest of Estes Park. Work started simultaneously from both sides.
• Crews spent four years, 1940-1944, drilling the tunnel. Work stopped twice due to demands during WWII.
• The two crews meet in the middle on June 10, 1944 and were only off by less than the width of a penny.
• The next three years, 1944 – 1947, the tunnel was lined with concrete and readied for water delivery.
• Water from the Colorado River first flowed east through the tunnel on June 23, 1947.
• The tunnel is 13.1 miles long and flows under Rocky Mountain National Park and Continental Divide, and the construction of the tunnel cost 12.8 million dollars.
• Adams tunnel is the longest tunnel in the US to provide water for irrigation.
• 213,000 acre-feet of water are delivered annually thru Alva B. Adams Tunnel.
• Alva B. Adams Tunnel delivers up to 1,100 acre feet of water in 24 hours.
• The tunnel is maintained by the US Bureau of Reclamation and is inspected once a year.

Colorado Big Thompson Project

• Largest trans-mountain water diversion project in Colorado
• Built between 1938-1957
• Provides water to 30 cities and town, used to irrigate 693,000 acres of northeastern Colorado farmland
• Made of 12 reservoirs, 35 tunnels, 95 miles of canals, and 700 miles of transmission lines
• Spans 150 miles east to west and 65 miles north to south
• West of the Continental Divide, water collects from the upper Colorado River in Willow Creek Reservoir, Shadow Mountain Reservoir, Grand Lake, and Lake Granby (all in Grand County, the start of the Colorado Big Thompson Project). Water is pumped into Shadow Mountain Reservoir where it flows into Grand Lake.
• From there, the Alva B. Adams Tunnels water under the Continental Divide to the eastern slope.
• Once water reaches the eastern slope, its used to generate energy as it falls almost half a mile through five power plants on its way to Colorado’s front range.
• Carter Lake, Horsetooth Reservoir, and Boulder Reservoir store the water delivered to the Front Range by the Colorado Big Thompson Project.
• Water is released as needed to supplement water supplies in the South Platte River Basin.
• The Colorado Big Thompson Project annually delivers 213,00 acre-feet of water to northeast Colorado for agriculture, municipal and industrial use. (all info taken from Northern Colorado Water Conservancy District)

Berthoud Ditch

• Built in 1910 owned by the cities of Northglenn and Golden
• Water diversion project to a tunnel that goes underneath Berthoud Pass
• Flows to Hoop Creek in the Clear Creek watershed to Standley Lake in Westminister

Grand Ditch

• A 14.3 mile long water diversion project owned by Water Supply and Storage Company
• Construction began in 1894 on this irrigation ditch approxiametly 100 feet above the Grand River Valley
• Sits at 10,175 feet above sea level
• Diverts water from the Colorado River, formerly the Grand River Valley (hence the name) on the west side of the Continental Divide and brings water to those east of the divide.
• Grand Ditch completed in 1934
• It intercepts approximately 1/3 of the surface watershed from the east side of Never Summer Range
• The Grand Ditch is very important to farmers of the Northern Colorado Plains
• 20,000 acres of water are delivered via the Grand Ditch through Rocky Mountain National Park to the eastern plains of Colorado
• Water ultimately flows into the Cache la Poudre River

Moffat Tunnel

• The Moffat Tunnel is a railroad passageway and water tunnel spanning 6.2 miles at over 9,200 feet.
• Tunnel was named after its visionary, David Moffat, a wealthy business man who knew Denver should be a stop on the transcontinental railroad in order to compete in commerce and to have a shorter route to Salt Lake City. David Moffat died before Tunnel was completed.
• Moffat Tunnel was first “holed through” February 18, 1926 after President Calvin Coolidge pressed a button in Washington DC that set off a blast of dynamite in Colorado. The program was broadcast by radio from the heart of the mountain.
• The Tunnel was completed in 1928, and the first train passed through the Moffat Tunnel in February 1928.
• Trains (California Zephyr) travel through the tunnel, but the main purpose of the Moffat Tunnel is to carry water to Denver and the Front Range from the Western Slope Fraser Basin.
• The Moffat Tunnel also gave coal and freight trains direct routes to major industry destinations.
• The Moffat Tunnel goes through James Peak and the Continental Divide, laying tracks in Grand County and continuing west.
• Railway traffic brought settlers to Grand County to take advantage of logging, livestock, and agricultural opportunities.
• The water delivered by the Moffat Tunnel is attributed to Denver and the Front Range’s ability to grow and thrive.
• The western portal of the Moffat Tunnel is located near Winter Park Ski Area. Foot traffic through the Tunnel is blocked, but it is very easy to see from the base of the mountain.
• If you are interested in traveling through the Moffat Tunnel contact Amtrak and ride the California Zephyr. Board the train in Denver and arrive at Fraser Depot (Two miles from Winter Park) in two hours.

Shoshone Power Plant

• Located in Glenwood Canyon along I-70 just north of the Colorado River
• The Shoshone Power Plant is a hydro-electric plant
• This engineering marvel was built in 1909, and today it generates 15 megawatts of green power for Excel Energy.
• Shoshone Power Plant plays a critical role in stream flow management, generating multiple uses of water in and along the Colorado River
• Power plant triggers release of water from reservoirs in Grand and Summit County.
• As a result, water flows down the Glenwood Canyon. The Upper Colorado enjoys a steady stream flow that benefits the environment, recreation and agriculture.
• Water that the plant diverts is not consumed. After it generates electricity, the water returns to the Colorado River - where it is used by rafters in Glenwood Springs, by towns along the middle of the Colorado River, and farther down stream for irrigation and agriculture in Grand Junction, CO.
• The central role of the plant is controlling river administration. The plant is vital to maintain a healthy Colorado River and sustains recreation and agriculture economies in Western Colorado.
• Windy Gap Project

Located just west of Granby

• The Windy Gap Project is a diversion dam on the Colorado River, 445-acre foot reservoir, a pumping plant, and a six mile pipeline to Lake Granby
• The dam is 27 feet high
• Delivers an average of 48,000 acre feet of water annually, between April and July mostly
• During Spring runoff, Fraser River is pumped from Windy Gap reservoir to Lake Granby where it is stored for delivery through the Colorado Big Thompson Project.