History
Northern Water Milestones
Northern Water has a rich history rooted in the development of the Colorado-Big Thompson (C-BT) Project. Established in 1937, the organization was created to partner with the U.S. Bureau of Reclamation to bring supplemental water from the Western Slope underneath the Continental Divide to support farms, communities and industry along Colorado’s Front Range.
Events Timeline
August 1884
State engineer E.S. Nettleton conducts the first preliminary survey of a possible diversion project to import West Slope water to the Front Range.
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1890
Irrigators construct small transmountain diversions to import water to the Poudre River basin.
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June 17, 1902
President Theodore Roosevelt signs the Reclamation Act (also known as the Newlands Act) into law, creating the United States Reclamation Service.
1905
The Reclamation Service withdraws land from public entry near Grand Lake for a potential future water diversion project.
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Jan. 26, 1915
The U.S. Congress establishes Rocky Mountain National Park. The enabling legislation includes the following: “The United States Reclamation Service may enter upon and utilize for flowage or other purposes any area within said park which may be necessary for the development and maintenance of a government reclamation project.”
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1921
The U.S. Congress officially changes the name of the Grand River to the Colorado River. Proponents request the change to officially identify the headwaters of the Colorado River and differentiate it from the Green River in Wyoming.
Nov. 24, 1922
Congress ratifies the first interstate river compact in the United States. The Colorado River Compact apportions the use of Colorado River water between the Upper (Colorado, Wyoming, Utah and New Mexico) and Lower (California, Arizona and Nevada) basin states.
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1930
The Great Depression hits. Drought and dust storms force many northeastern Colorado farmers to halt all efforts to raise crops.
Aug. 17, 1933
Northern Colorado leaders organize the Grand Lake Committee – predecessor to the Northern Colorado Water Users Association and the Northern Colorado Water Conservancy District (NCWCD/Northern Water) – to pursue a Grand Lake water diversion project.
Jan. 25, 1935
Grand Lake Project proponents establish the Northern Colorado Water Users Association.
July 1, 1936
Congress officially renames the Grand Lake Project the Colorado-Big Thompson Project.
May 13, 1937
Colorado Governor Teller Ammons signs the Conservancy District Act into law.
June 15, 1937
U. S. Senator Alva B. Adams presents Senate Document 80 to Congress (a development plan and cost estimates for the C-BT Project).
June 24, 1937
Congress approves Senate Document 80, authorizing construction of the C-BT Project.
Aug. 9, 1937
President Roosevelt signs the Interior Department appropriations bill committing $900,000 in construction funds to the C-BT Project.
Sept. 20, 1937
The District Court of Weld County orders the creation of Northern Water.
Sept. 28, 1937
The Northern Water Board of Directors meets for the first time in the basement of the Greeley Tribune building. This location is Northern Water's headquarters until May 27, 1954.
June 28, 1938
Northeastern Colorado voters authorize Northern Water to sign a contract with the United States and to assess a 1 mill ad valorem tax on all properties within Northern Water boundaries to build and operate the C-BT Project. The measure is approved by a 17:1 margin.
July 5, 1938
Northern Water signs a contract with the United States to repay a portion of C-BT Project construction costs.
Dec. 1, 1938
Warner Construction Company begins excavating the foundation for Green Mountain Reservoir dam, the first major C-BT Project feature constructed.
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June 23, 1940
Construction begins on the Continental Divide Tunnel. One crew begins from Grand Lake on the West Slope while a second team tunnels from a location near Estes Park on the East Slope. When complete the tunnel is the longest ever built from two separate headings.
Dec. 5, 1941
Work begins on the Lake Granby Dam and diversion tunnel.
May 1943
Green Mountain Power Plant produces its first electricity.
April 24, 1944
Work on Shadow Mountain Dam begins. The War Production Board grants special allowance for continued C-BT Project construction for war-time food production.
June 10, 1944
Crews working from both the West and East slopes hole through the Continental Divide Tunnel. NBC radio broadcasts the event live to the nation. A check of the center line and grade reveals the two sides are off by only a penny's width.
Dec. 21, 1944
President Roosevelt signs legislation to rename the tunnel after the late Senator Alva B. Adams.
November 1945
Construction workers complete Shadow Mountain Dam and spillway.
June 23, 1947
Ten years after work began on the C-BT Project, and seven years to the day after tunnel construction began, officials dedicate the Adams Tunnel. The first C-BT water is delivered to the East Slope.
Nov. 1, 1948
Crews close the gates at Olympus Dam, enabling water to be stored in Lake Estes.
Sept. 14, 1949
Water is stored in Lake Granby for the first time.
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July 19, 1950
Work begins on the dams at Carter Lake.
Jan. 10, 1951
Water is stored for the first time in Horsetooth Reservoir.
Jan. 25, 1951
Water is pumped from Lake Granby into Shadow Mountain Reservoir for the first time.
July 20, 1951
Colorado Gov. Lee Knous and others dedicate the Granby Pump Plant and sponsor a fishing contest in conjunction with the ceremony.
July 21, 1951
The first C-BT Project water is released from Horsetooth Reservoir into the Poudre River.
Sept. 19, 1952
Crews finish building the dams at Carter Lake.
April 2, 1953
Water is stored in Willow Creek Reservoir for the first time.
Sept. 8, 1953
The Northern Water Board votes to include the City of Boulder in District boundaries.
Feb. 26, 1954
Water is pumped from Flatiron Reservoir into Carter Lake for the first time, bringing Colorado River water to the Little Thompson and St. Vrain valleys.
May 27, 1954
After 17 years in the basement of the Greeley Tribune building, Northern Water moves to its new headquarters west of Loveland. The District has four full-time employees.
Jan. 1, 1956
Construction crews finish the South Platte Supply Canal, the final C-BT Project feature Congress authorized in 1937.
Aug. 11, 1956
Northern Water officials rename the Horsetooth Feeder Canal and the Poudre Supply Canal in honor of Charles Hansen, Greeley Tribune editor, C-BT Project proponent and first Northern Water Board president.
1957
The C-BT Project is declared complete and fully operational.
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Nov. 9, 1960
A Weld County District Court order expands the Northern Water Board from 11 to 12 directors. The additional appointee represents Boulder County, which has experienced a 53 percent population increase between 1950 and 1960.
October 1965
Engineers rebuild Granby Dam spillway after discovering the original design allows water to undercut bedrock adjacent to the dam's base.
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July 6, 1970
Windy Gap Project participants formally establish Northern Water's Municipal Subdistrict, the first subdistrict ever created under the Water Conservancy Act. Construction begins on a new Northern Water headquarters.
April 27, 1971
Northern Water moves into its new headquarters at 1250 N. Wilson Avenue in Loveland. This location serves as the organization’s principal place of business until August 28, 2003.
July 31, 1976
A flash flood on the Big Thompson River kills 145 people and causes more than $35 million in property damage. Flood water and debris destroy the 240-foot-long Big Thompson Siphon, halting C-BT Project water deliveries to Horsetooth Reservoir. Reclamation officials oversee fabrication and installation of a new siphon is operational in 88 days.
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July 11, 1981
Construction crews break ground on the Windy Gap Project.
June 29, 1985
Subdistrict officials dedicate the Windy Gap Project.
June 1, 1986
Northern Water assumes operation and maintenance responsibilities for C-BT collection facilities on the West Slope.
October 1986
U.S. President Ronald Reagan signs legislation designating a large segment of the Cache la Poudre as Colorado's first wild and scenic river.
Sept. 20, 1987
Northern Water marks its 50th anniversary with a celebration at its headquarters in Loveland.
1988
Engineers raise Horsetooth’s four dams 3 to 8 feet in elevation from 1988 to 1989, increasing the reservoir's ability to store water from major flood events and addressing safety concerns.
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June 14, 1991
Northern Water and Subdistrict boards vote to include the City and County of Broomfield within Northern Water and Subdistrict boundaries.
October 1992
The University Press of Colorado publishes "The Last Water Hole in the West," a history of Northern Water and C-BT Project. The book's author is Colorado State University historian Daniel Tyler.
November 1993
Construction begins on the Southern Water Supply Project pipeline from Carter Lake to Broomfield.
June 18, 1994
Officials rename the Granby Pump Plant in honor of the Farr family, a prominent Weld County farm and ranching family.
Dec. 13, 1995
A rare sequence of events triggers an explosion at the Flatiron Power Plant’s Unit No. 3. Reclamation must repair the unit before it can pump water to Carter Lake.
May 1, 1996
The Subdistrict and dignitaries dedicate and open the Windy Gap Watchable Wildlife Area for public use at Windy Gap Reservoir near Granby.
1999
Windy Gap Project participants and the Subdistrict consider several potential reservoir sites on both the East and West slopes to store Windy Gap Project water from 1999 to 2000. This effort becomes known as the Windy Gap Firming Project, an effort to firm the relatively junior Windy Gap Project water rights and provide storage independent of the C-BT Project.
September 1999
Crews finish work on the Southern Water Supply Project pipeline’s final 42 miles from Platteville to Fort Morgan.
Events Timeline
June 13, 2000
The Bobcat Gulch fire ignites north of Drake and west of the Hansen Feeder Canal. The fire scorches approximately 10,600 acres. Northern Water and other agencies cooperate to minimize erosion and excessive runoff from the burned area.
August 2002
A contractor repaints the Big Thompson Siphon, the structure’s first new coat of paint since it was replaced following the 1976 Big Thompson flood. The new color: sweetwood brown.
October 2002
The Northern Water Board moves its initial quota declaration to October, establishing winter-time water delivery accounts and allowing water users to transfer water before the traditional quota declaration each April.
December 2002
Northern Water makes its final payment to the federal government, fulfilling its financial obligations under the original C-BT Project Repayment Contract and the C-BT Project Supplemental Contract No. 2. Northern Water continues to repay its portion of Horsetooth Modernization Project costs under C-BT Project Supplemental Contract No. 7.
2003
Chimney Hollow Reservoir Project participants enter the federal permitting process and U.S. Bureau of Reclamation holds three formal "scoping" meetings.
April 2003
The Subdistrict pumps a record-setting 64,200 acre-feet of Windy Gap Project water to Lake Granby.
Sept. 2, 2003
After more than 49 years in west Loveland, Northern Water moves to its new facility in Berthoud. The District has 104 full-time employees; 84 in Berthoud and 20 at the Farr Pump Plant on Lake Granby.
March 2004
Crews finish constructing the Pleasant Valley Pipeline between Horsetooth Reservoir and the Poudre River. It is designed to flow by gravity in each direction without the need for pumps, associated infrastructure or power costs.
April 2004
Northern Water expands its water quality monitoring program, a multi-agency effort to monitor and maintain the C-BT Project’s supply of high-quality water.
October 2005
The Northern Water Board adopts a Regional Pool Program to increase water management flexibility and help preserve a portion of C-BT Project water supplies for irrigated agriculture.
July 31, 2006
Northern Water dedicates its Outdoor Laboratory for Landscape and Irrigation Education (OLLIE) and marks the 30th anniversary of the 1976 Big Thompson flood. OLLIE, a 2.5-acre site dedicated to turf, soil, irrigation and planting experiments, is part of Northern Water's Turf and Urban Landscape Water Management & Conservation Program. In 2007 OLLIE is renamed The Conservation Gardens at Northern Water.
October 2007
A new outlet is constructed at Carter Lake. Completed in March 2008, the project includes a three-tiered intake tower, an 800-foot-long tunnel and several hundred feet of pipeline. The additional outlet supplements rather than replaces the original outlet structure.
Events Timeline
October 2010
Northern Water rehabilitates the connecting channel structure between Grand Lake and Shadow Mountain Reservoir. Built in the mid-1940s, the structure helps control surface levels in both water bodies.
2011
U.S. Bureau of Reclamation publishes the Final Environmental Impact Statement for the Chimney Hollow Reservoir Project.
2012
Grand County and the Municipal Subdistrict board approve agreements to create improvements to the Colorado River. Grand County issues 1041 permit for the Chimney Hollow Reservoir Project.
May 31, 2012
Northern Water dedicates the Robert V. Trout Hydropower Plant at Carter Lake. Named for Bob Trout, Northern Water’s legal counsel for more than 35 years, the $6-million project includes two 1,300 kilowatt Francis turbines with a projected output of 7 to 10 million kilowatt-hours per year, enough to power about 1,000 homes.
June 9, 2012
The High Park Fire is detected west of Fort Collins. Caused by a lightning strike, the fire burned over 87,284 acres, destroyed 259 homes and negatively impacted water quality in the Cache la Poudre River. By land area the High Park Fire was the second-largest in Colorado history.
Sept. 20, 2012
Northern Water marks its 75th anniversary with a celebration at its headquarters in Berthoud.
September 2013
Beginning on September 9, 2013, a slow-moving cold front stalls over Colorado and clashes with warm humid monsoonal air from the south, resulting in heavy rain and catastrophic flooding along Colorado's Front Range. The situation intensifies on September 11 and 12, when rainfall totals exceed 20 inches in parts of Boulder County, leading to flash flooding, loss of life and property destruction (including C-BT Project infrastructure).
June 3, 2016
Northern Water dedicates the Granby Hydropower Plant at the base of Granby Dam. The $5.1-million project includes two 600 kilowatt Francis turbines with a projected output of 5 million kilowatt-hours per year, enough to power about 370 homes.
May 16, 2017
The U.S. Army Corps of Engineers issues a Record of Decision enabling the Subdistrict to proceed with construction of Chimney Hollow Reservoir, the key component of the Windy Gap Firming Project.
May 2018
Construction begins on a second Southern Water Supply Project pipeline (SWSP II) from Carter Lake. The $44 million pipeline parallels the first SWSP pipeline from Carter Lake to the west side of Longmont. From there the new pipeline will head southwest to serve both the Left Hand Water District and the City of Boulder’s water filtration plant at Boulder Reservoir.
Events Timeline
- January 2020
- September 2020
- Sept. 2, 2020
- October 2020
- Dec. 10, 2020
- Feb. 12, 2021
- April 21, 2021
- May 13, 2021
- June 17, 2021
- Aug. 6, 2021
- Aug. 16, 2021
- Feb. 9, 2022
- April 2022
- June 1, 2022
- Aug. 23, 2022
- September 2022
- Sept. 15, 2022
- Oct. 15, 2022
- Dec. 9, 2022
- May 25, 2023
- July 10, 2023
- Oct. 25, 2023
- March 13, 2024
- March 23, 2024
- June 2024
- October 2024
- Nov. 19, 2024
- July 18, 2025
- August 2025
- Dec. 19, 2025
- April 20, 2026
January 2020
The Water Quality Control Division of the Colorado Department of Public Health and Environment issues the Northern Integrated Supply Project the Colorado 401 Water Quality Certification.
September 2020
Colorado experiences devastating wildfires on the East and West slopes. The East Troublesome, Cameron Peak, Calwood and Williams Fork fires each present hazards to residents and infrastructure in watersheds tributary to the Colorado-Big Thompson and Windy Gap projects.
Sept. 2, 2020
The Northern Integrated Supply Project achieved an important milestone with the Larimer County Board of County Commissioners approving the 1041 Land Use Permit application.
October 2020
Due to unprecedented growth of the East Troublesome fire in Grand County, control center operations are transferred from the Farr Pump Plant to Northern Water’s Berthoud headquarters. Northern Water and the U.S. Bureau of Reclamation work jointly to protect C-BT Project infrastructure, including closing the Adams Tunnel and halting pumping operations at Lake Granby. A late October storm blankets both East and West slope fire areas with 12-18 inches of snow, halting expansion of the fires and allowing most of the C-BT Project’s West Slope facilities to resume operations.
Dec. 10, 2020
Federal Court rules in favor of the Windy Gap Firming Project, clearing the way for construction of Chimney Hollow Reservoir near Berthoud.
Feb. 12, 2021
The Northern Water Board of Directors and Grand County Board of County Commissioners agree to be sponsors for the Emergency Watershed Protection Program for the East Troublesome Fire recovery effort and for the Grand County Watershed Recovery group. The EWP Program is managed by the U.S. Department of Agriculture’s Natural Resources Conservation Service. Its purpose is to implement watershed protection projects that mitigate risks to life and property caused by sudden watershed impairments such as post-fire flooding, sediment loading and debris flows.
April 21, 2021
The Municipal Subdistrict reaches an agreement with several environmental groups settling the lawsuit and appeal. The $15 million settlement will benefit aquatic habitat on the West Slope. The settlement will allow construction of Chimney Hollow Reservoir beginning in August 2021.
May 13, 2021
Northern Water broke ground on Phase I of its Berthoud Campus Development Project. Phase I includes construction of Building F to house the Operations Division, buildings H and K for fleet and long-term storage, as well as parking lot expansion and other site improvements.
June 17, 2021
Northern Water breaks ground on its new Willow Creek Campus in Grand County, Colorado. The new campus will be located just south of our Willow Creek Pump Plant on land owned by Northern Water. The campus building will be approximately 41,000 square feet and will be a mix of office and fleet maintenance space, as well as home to our control room. The new campus will house approximately 30 full-time employees and is intended to replace the existing office/shop facilities at Farr and Windy Gap pump plants.
Aug. 6, 2021
The Northern Water Municipal Subdistrict breaks ground on Chimney Hollow Reservoir, culminating a 20-year permitting process. Chimney Hollow Reservoir is a key component for these Windy Gap Firming participants: Broomfield, Platte River Power Authority, Loveland, Greeley, Longmont, Erie, Little Thompson Water District, Superior, Louisville, Fort Lupton, Lafayette and Central Weld County Water District. Each of the reservoir project participants that provide residential water service has committed to reduce per capita water supply through water conservation.
Aug. 16, 2021
Northern Water’s Municipal Subdistrict issued a Notice to Proceed to Barnard Construction Co. Inc. to begin construction of Chimney Hollow Reservoir. Environmental and mitigation efforts have also begun in the Upper Colorado River basin.
Feb. 9, 2022
In what is described as a “milestone” day, crews install a bridge to connect two sections of a new Larimer County access road at the Chimney Hollow Reservoir construction site.
April 2022
The Northern Water Board of Directors is expanded to 13 members. The additional member represents the City and County of Broomfield.
June 1, 2022
The Northern Water Board dedicates the Eastern Pump Plant. The plant includes four pumps that increase the capacity of the Southern Water Supply Project by 63 percent. The facility was designed in 2018, and work began on the $10 million project in early 2020. Despite the challenges of the COVID-19 pandemic and a tightened supply chain, crews were able to complete the project on budget and within its design parameters.
Aug. 23, 2022
Dignitaries from across the region gather to celebrate the start of construction at the Colorado River Connectivity Channel located in Grand County. Led by U.S. Sen. Michael Bennet, leaders of public agencies and private non-governmental organizations extol the value of the project that will reconnect two segments of the Colorado River above and below Windy Gap Reservoir.
September 2022
West Slope employees move into the new Willow Creek Campus, the first Northern Water office and maintenance complex on the West Slope. Employees worked out of various locations, including Farr and Windy Gap pump plants, since Farr Pump Plant was constructed from 1947 to 1951. The new building offers a mix of office and fleet maintenance space, as well as a control room to allow staff to manage Northern Water facilities.
Sept. 15, 2022
A shutdown of the Colorado-Big Thompson (C-BT) Project goes into effect as crews cut into the existing C-BT infrastructure at the Bald Mountain Tunnel. A 126-inch steel pipe with a 72-inch steel offtake (known as a wye) is tied-in so that future water deliveries can be made to Chimney Hollow Reservoir.
Oct. 15, 2022
Crews place the first section of the asphalt core on the Chimney Hollow main dam. The asphalt is placed in 10-inch lifts until it reaches the top of the dam (approximately 350 feet). Rockfill occurred concurrently to stabilize the asphalt core.
Dec. 9, 2022
The U.S. Army Corps of Engineers issues a federal Clean Water Act Section 404 Record of Decision for the Northern Integrated Supply Project. This is a major milestone for NISP, as it reflects the lead federal regulatory agency’s review and approval of the project. The Corps’ approval is based on a lengthy and rigorous scientific analysis under the National Environmental Policy Act and a host of other environmental laws, including the federal Endangered Species Act, National Historic Preservation Act, State Water Quality compliance certification, and State Fish and Wildlife Mitigation Plan requirements.
May 25, 2023
The final beam of the Building A expansion is placed. The expansion is part of the Phase II Campus Development Project at the Berthoud Headquarters.
July 10, 2023
The highest daily total for the C-BT Project occurs when 803,291 acre-feet of water is in storage, surpassing the previous record set on July 14, 2019, by 769 acre-feet.
Oct. 25, 2023
First water flowed through the Colorado River Connectivity Channel. The new channel around Windy Gap Reservoir hydrologically and ecologically reconnected two segments of the Colorado River for the first time in approximately 40 years.
March 13, 2024
Crews hole through on Chimney Hollow Reservoir Project inlet/outlet tunnel, connecting the upstream and downstream portions.
March 23, 2024
The Chimney Hollow main dam hits halfway mark of 175 feet.
June 2024
Northern Water employees move into the newly expanded Building A at the Berthoud campus, marking the completion of a multi-year campus development project. On June 13, 2024, the Board of Directors and employees gather for a ribbon cutting to mark the project completion. The campus development project includes construction of several new buildings for staff and storage, as well as parking lot expansion and other site improvements. The additional offices and expansion allow Northern Water to meet long-term project needs.
October 2024
Colorado River Connectivity Channel (CRCC) completed. Construction got underway in the summer of 2022, and by Oct. 25, 2023, the project was far enough along to send the first flows into the new channel. The Colorado River Connectivity Channel is part of a $90 million package of environmental measures associated with construction of Chimney Hollow Reservoir near Loveland, which is where Windy Gap water will be stored once construction is complete in 2025.
Nov. 19, 2024
Final lift of clay placed on the Chimney Hollow Reservoir saddle dam.
July 18, 2025
Final lift of asphalt placed on the main dam at Chimney Hollow Reservoir.
August 2025
Chimney Hollow Reservoir main dam topped off.
Dec. 19, 2025
Chimney Hollow Reservoir Project substantial completion reached.
April 20, 2026
Northern Water begins moving 1,500 acre feet of water into Chimney Hollow Reservoir to continue water quality testing and modeling, as well as to commission the hydraulic infrastructure in the valve house. This initial fill lasted 12 days.