Colorado-Big Thompson Project

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Colorado-Big Thompson Project (85 KB)

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Construction

The dam embankment contains about 3.5 million cubic yards of clay, sand, and gravel roller compacted in six-inch layers. The capacity of the reservoir is 154,600 acre-feet. The width of the embankment`s base is 1,500 feet eventually narrowing to a 40-foot wide crest. The dam`s downstream face is made up of 740,000 cubic yards of cobblestones and coarse rock. Green Mountain also contains outlet works, a 1,070 foot concrete-lined open channel spillway, and a hydroelectric generation plants containing two generators. The primary source of rock came from a borrow pit on the left abutment above the dam site. Overseeing activities were Reclamation construction engineer R.B. Ward and Warner general superintendent J.D. Fogg.(20) Because of the site`s remoteness and the severity of high country winters, most construction at Green Mountain Dam was seasonal. Attempting to avoid excessive delays, Reclamation extended the existing road from Kremmling -- the nearest railroad point -- to the dam and camp. Warner built a small town on the left bank of the Blue River, 1,200 feet upstream from construction. The camp consisted of 25 bunkhouses, commissary, mess hall, warehouse, and field offices. On average, the bunkhouses sat 200 chilly feet away from the community bathhouse. Early in construction, trailers, small shacks, and tents bloomed near the work site. In an attempt to comply with sanitary regulations, Warner laid gravel roads and installed water, sewer and street-light systems. Workers had to pay $6 per month for a space of 30 x 40 feet, electricity, use of the laundry room, and trash collection and disposal. Reclamation`s headquarters camp was a thousand feet upstream from the southwest end of the dam. A one room school barracks held 39 to 46 grade school children and five to eight high schoolers. During CBT`s next eighteen years, the government built four other camps on the project (Estes, Shadow Mountain, Loveland and Fort Collins) to house laborers.(21) Controversy again followed CBT during its first spring and summer of construction. On July 12, 1939, a strike was called by five American Federation of Labor (AFL) craft unions to support demands for collective bargaining recognition and a closed shop. The State Industrial Commission called the shutdown illegal, because union officials failed to comply with a Colorado statue requiring 30 days notice of intention to strike. The NCWCD also came out against labor`s walkout, saying they were in favor of an open shop to hire non-union men. For two-and-a-half weeks, there were no direct negotiations between the union and Warner. A Department of Labor mediator, P.W. Chappell, separately consulted with both factions to resolve the issue. Reclamation chose to stay on the sidelines, according to engineer Preston, as the strike was `a matter for the contractor and workers to settle between themselves.`(22) Summit County, home of Green Mountain Dam, swirled in rumors of local unionists phoning Denver`s AFL headquarters for 500 reinforcements and `dozens of cars and trucks carrying an estimated five hundred Mexicans, Negroes and hard cases` on route to the mountains to join the strikers. Warner tried to hire strikebreakers, and at 4:30 on the afternoon of August 1, an anti-union caravan headed toward the main gate only to find the road littered with structural iron and equipment. Leading the strikebreakers` charge was a local blacksmith, Dan Hore, who `drove his car squarely against the wooden gate, smashing it down.` Behind Hore, a `back to work` force of `100 former employees and 100 ranchers and businessmen,` quickly dispersed the pickets. Described by a Denver newspaper, the strikebreakers were, `Jumping from their cars,` driving `the picket force aside by sheer force of numbers.` At the end of the day, two picket lines had been broken. The sole injury belonged to one strikebreaker, his scalp cut by a flying rock.(23) On August 4, Colorado Governor Ralph Carr called out a National Guard force equipped with rifles, machine guns, and two tanks. The Governor wished the disturbance would resolve itself not only for the state`s image, but the Guard was draining the state treasury at a rate of $1,000-a-day. Carr declared Martial law in Grand and Summit counties, as negotiations between all parties continued. On August 22, Warner and the AFL reached agreement, and the union won permission to sign a closed shop agreement on September 15. In Greeley, the NCWCD Board expressed its anger at Warner for ending the strike by voting to bill the company for the cost of sending men to Green Mountain to participate in the negotiations. In Washington, Ickes resented NCWCD meddling in the hiring of men on a federal project. Early in September, he told a press conference, `The Northern Colorado Water Conservancy District favored an open shop policy to encourage hiring of workers from the area . . . an area of chiefly unorganized labor.` He added, `The proposition that non-urban labor should have first call on the jobs appears unfair to me in the face of the great unemployment in labor in the larger cities.`(24) In the following years, one other major labor flare-up happened. In February 1941, approximately 100 AFL members excavating the Alva B. Adams tunnel stopped work protesting the federally mandated wage scale for tunnel bore workers. The Department of Labor`s minimum wage scale remained, but the union struck a deal with S.S. Magoffin Co., of Englewood, Colorado, contractors of the first tunnel boring unit. Wages increased from 80 cents to $1.10 an hour for tunnel miners and from $1.10 to $1.25 for mechanics and mucking machine operators.(25) With the agreement between Warner and the AFL, management, engineers and laborers now began to concentrate on the crowning feature of the CBT. On June 15, 1940, a dynamite blast signalled the beginning of a six year odyssey. It was man against rock in a test of wills to carve out the world`s longest tunnel drilled from two locations. Back in the pre-authorization and planning days of 1936, discussions among Reclamation engineers took place on how to clear the tunnel without damaging the surrounding environment. Explosive charges, or shots, would be placed at a depth where they would not blow out a hole, but only heave the surface slightly so as the leave no noticeable scars. Care also had to be exercised in placing the charges far enough away from trees. Contracts for excavation were divided among several firms. Platt Rogers, Inc. of Pueblo, would excavate the first 6,600 feet from the west portal. The first 8,000 feet of the east portal contract belonged to S.S. Magoffin Co. On February 3, 1941, Magoffin won an additional agreement to continue excavation from the east portal. On June 26, 1941, Stiers Brothers Construction Co. of St. Louis received the contract to continue from the west portal.(26) In December 1941, while work on the Continental Divide Tunnel continued, teams of laborers and engineers began the centerpiece of the West Slope collection structures, Lake Granby. The bowl shaped lake stores 539,800 acre feet for diversion to the Eastern Slope. The man-made lake is 5.5 miles northeast of the town of Granby and ten miles down stream from Grand Lake. The rock and earthfill Granby Dam and four dikes collect water from the Colorado River and its tributaries and saves it for pumping into Shadow Mountain and Grand Lakes. Lake Granby`s additional storage comes from the waters of Willow Creek, a westerly tributary entering the Colorado River below Granby Dam. Built between 1951 and 1953, moisture caught by the Willow Creek Dam is lifted 175 feet by pumps into Lake Granby. Willow Creek reservoir holds 10,443 acre-feet and has a 400 cubic feet per second (cfs) feeder canal extending two miles from the reservoir to the Willow Creek pumping plant. On Lake Granby`s northeast corner is another pumping plant standing 12-stories high, partly submerged in the bank of the reservoir.(27) Between Lake Granby, and below Grand Lake, sits Shadow Mountain Lake. The lake is formed by Shadow Mountain Dam, 11 miles northeast of Granby on the north fork of the Colorado River. Lake Granby water rises 125 feet from the Lake Granby Pumping Plant into a canal on a 1.8 mile journey to Shadow Mountain Reservoir. From the reservoir water flows into Grand Lake and then over a fixed weir into the mouth of the Adams Tunnel. A rockfill embankment, the East Portal Dam, is 750 feet below the east portal of the tunnel. The dam creates a pond for the regulation of outflow from Adams Tunnel and provides a headworks for the Aspen Creek Siphon to deliver water to Marys Lake. Construction on Shadow Mountain Dam and dikes lasted from April 1944 to August 21, 1946.(28) World events intervened in the completion of the CBT. On November 15, 1942, the War Production Board (WPB) suspended all work to conserve steel and other vital war material. On the last day of 1942, construction on all project features came to a halt, except Green Mountain Dam and Powerplant. By the last week of May 1943, the Green Mountain Powerplant generating units supplied power to war plants in Denver. Work brought to a standstill included the Granby Dam diversion outlet tunnel, Granby Dikes 1, 2, and 4 and the remaining 2.5 miles of the Continental Divide Tunnel. Northern Coloradans with a large stake in the project`s quick completion met with several administrative agencies in the nation`s capital. Their efforts prompted a project review by the War Food Administration, Reclamation, and the WPB, and resulted in resumption of work on the tunnel in August 1943.(29) On March 31, 1944, crews drilling the Continental Divide Tunnel from the west heard blasts from the eastern face 4,245 feet away. For safety`s sake, work on the west side stopped June 7, 1944. On June 10, at 12:24 p.m., light was seen through both ends of the tunnel, as NBC Radio broadcast the moment live to the rest of the nation. Twenty minutes later, nine charges of dynamite blew out the remaining rock and that afternoon men from both sides met face to face under the Divide. On December 21, 1944, President Roosevelt signed legislation posthumously honoring Senator Adams for his support for and belief in the Colorado-Big Thompson Project. The Continental Divide Tunnel would begin service as the Alva B. Adams Tunnel.(30) After excavation, and before the tunnel provided deliveries, the 9-foot, 9-inch unreinforced tunnel was lined with a one-foot thick concrete ring for water passage. A 69 Kilovolt transmission line, encased in a pipe running along the roof of the tunnel, connected east and west slope power facilities. At the beginning of 1945, war material demands curtailed work on the tunnel one final time. However, the organization responsible for allocating workers to federal project, the War Manpower Commission (WMC), permitted both contractors to hire one shift of workers to complete the tunnel lining. In August, both the war and government restrictions ended, construction slowed only for delayed congressional appropriations, Reclamation scheduling, and temporary shortage of some materials.(31) Time spent in excavating and lining the tunnel was either anxious or monotonous with flashes of the unexpected. Tunnelers spent long hours underground in the dark, moving forward, shot by shot. Everyday worries included cave-ins, discovering an underground stream that could flood excavation, and power cables blowing up and throwing the tunneling into complete darkness while concrete continued to flow. In the winter, numbingly cold temperatures formed ice stalagmites.(32) Construction of the project began at Green Mountain Dam during November 1938. The first power was generated at the Green Mountain Powerplant in May 1943; all construction of the dam and powerplant was completed in October 1943. Construction of Granby Dam started in 1941, and of Alva B. Adams Tunnel in the summer of 1940. Work was curtailed during World War II, but not entirely stopped. At the end of the war, the tempo of construction was speeded up. During 1956, all major features were essentially completed except the Big Thompson Powerplant, which was completed in 1959. The Colorado-Big Thompson Project helps stabilize the agricultural and industrial economy of northeastern Colorado. It is particularly effective each year during late summer months of the irrigation season, and has a tremendous impact throughout the season in drought years. Principal crops include sugar beets, potatoes, beans, corn, small grains, fruits, alfalfa, vegetables, dairy products, poultry, and eggs. In addition, lambs, hogs, and cattle are fattened from the byproducts of the sugar beets. Municipal supplies have been an important aspect in the distribution of project water. Originally, nine communities had allotments totaling 44,950 acre-feet. Eleven communities now receive full or supplemental supplies. Each year, as urban population increases, irrigation allotments are transferred to domestic purposes. The dependable availability of water continues to attract a variety of industries. About two million people visit the man-made lakes annually to enjoy fishing, motor and sail boating, water skiing, swimming, camping, hiking, and picnicking. Trout, kokanee, bass, walleye, and perch are the principal fish caught in the clear, cool waters. Ice fishing and snowmobiling have become favorite winter sports. For specific information about any of these recreation sites, click on the name below. http://www.recreation.gov/detail.cfm?ID=49 http://www.recreation.gov/detail.cfm?ID=51 http://www.recreation.gov/detail.cfm?ID=52 http://www.recreation.gov/detail.cfm?ID=65 http://www.recreation.gov/detail.cfm?ID=66 http://www.recreation.gov/detail.cfm?ID=67 http://www.recreation.gov/detail.cfm?ID=68 http://www.recreation.gov/detail.cfm?ID=88 http://www.recreation.gov/detail.cfm?ID=89 http://www.recreation.gov/detail.cfm?ID=699 http://www.recreation.gov/detail.cfm?ID=9 http://www.recreation.gov/detail.cfm?ID=94 From the eastern portal of the Alva B. Adams Tunnel, water descends about 2,800 feet to the foothills. Nearly every foot of the head is used for hydroelectric power generation. Gross generation averages 760 million kilowatt-hours of which 70 million kilowatt-hours are used by project pumps and 690 million kilowatt-hours are marketed to customers in northern Colorado, eastern Wyoming, and western Nebraska. The power produced at the Bureau powerplants is marketed by DOE. The water and power control center for Reclamation`s reservoirs, powerplants, and transmission lines in Wyoming, Colorado, and western Nebraska is at the project headquarters in Loveland, Colorado. This Western Division of the Missouri River Basin is an interconnected system of 15 Reclamation powerplants and 391,750 kilowatts of installed capacity. The Colorado Big Thompson Project has provided an accumulated $316,000 in flood control benefits from 1950 to 1999. From planner`s dreams to blueprints to everyday operation, notoriety has been the companion of the Colorado-Big Thompson Project at every step. The challenge of harnessing the Western Slope headwaters of the Colorado River to service the state`s Eastern Slope plains came with a series of natural and man-made roadblocks. In confronting this challenge, Reclamation not only tackled a mountain range and the laws of gravity, it fought fraternal squabbles with other Federal agencies, dealt with protests over the preservation of Rocky Mountain National Park, oversaw squabbles between Western Slope and Eastern Slope Colorado, and waited through labor disputes, water rights wrangles, material and manpower shortages, and delays resultant from World War II. Reclamation designed the Colorado-Big Thompson, or CBT, to collect and deliver up to 310,000 acre-feet of water annually from the Colorado River Basin. High in the Rocky Mountains, the project gathers snowmelt for four dams and pumps upwards to a similar number of reservoirs. Moisture is transported west to east 3,800 feet beneath the Continental Divide through the 13.1-mile Alva B. Adams Tunnel. On the eastern third of its journey, the water cascades down to the different diversion structures for delivery to farms and an increasing number of housing developments. The entire project contains more than 100 major features, 125 water user organizations, 60 reservoirs and many distribution canals. In two decades, this Rocky Mountain saga helped transform Northern Colorado into one of the nation`s most productive agricultural regions, and laid the foundation for a tract-home land rush along the state`s Front Range. It starts with white snows and gray winters and runs from the pine trees and peaks down beneath the 14,000 foot Continental Divide before stopping in the tall grass prairies of Colorado`s northeastern corner. The terrain covered by the Colorado-Big Thompson is a tour across the climates and regions within the state`s borders. The CBT Project spans 250 miles east-to-west from Brush on the high plains of Eastern Colorado to Kremmling in the high mountains of Western Colorado. The service area stretches 65 miles north-to-south from near the Wyoming border to the city of Boulder. The CBT furnishes supplemental water to approximately 720,000 acres and more than 400,000 people in the South Platte River Basin. It also provides power to the towns of Longmont, Loveland, Boulder, Fort Collins, Greeley, Fort Morgan, and Sterling, and overall, eleven communities receive municipal and industrial water from the project. In Colorado, precipitation is the treasure that gets harder to find farther down the peaks or on the eastern slope. Elevations over 10,000 feet usually receive 30 inches or more a year of moisture in the form of rain, snow, sleet, and hail. Only in July and August does the average daily minimum temperature work its way above freezing. At Grand Lake, (elev. 8,369 feet), yearly moisture averages 16 inches. East of the mountains average annual totals drop to 12.5 inches at Greeley, but increases to 16.5 inches a year at Julesburg, near the Nebraska line. The eastern slope is the extreme western Great Plains, and has a climate of warm, sunny days during the spring and summer and cool nights favorable for agriculture.(1) Directed by newspaper editor Horace Greeley`s admonition to `Go west and grow up with the country,` the settlers of the Union Colony, later to become Greeley, Colorado, built their community in the spirit of the pundit`s words. They soon discovered their new settlement desperately needed water. The shallow valleys and flat prairies of the South Platte River and its tributaries were home for the buffalo, but dry, bare of trees and other vegetation. Soon after their arrival in the 1860s, northeastern Colorado pioneers plowed small ditches from nearby creeks to irrigate a few acres of land. In 1870, the Union Colony boasted 2,000 people and irrigated about 12,000 acres along the Cache la Poudre River. The following year, the colonists built the first planned irrigation ditch in Colorado Territory, the 27-mile long Greeley Canal No. 1. Similar irrigation enterprises followed at Fort Collins, Longmont, and Loveland. A series of water rights disagreements among different small towns led to the creation of Colorado`s innovative irrigation laws. The lessons learned on the high plains were enacted into the state`s water codes and establishment of water districts in 1879. The close of the nineteenth century saw a spate of reservoir construction in northern Colorado aided by a decade of above average precipitation. By 1910, the limitations of the reservoirs then in use stimulated discussion among farmers, businessmen, and engineers on the possibility of transmountain diversion to the plains.(2) The idea of mastering the Colorado River had been kicking around the state for at least thirty years. In 1889, the legislature appropriated $20,000 for a survey led by state engineer K.P. Maxwell. His job was to research the feasibility of drilling a tunnel from Monarch Lake on a Colorado River tributary to St. Vrain Creek, a tributary of the South Platte. The legislature also spent $3,000 to survey the possibilities of diverting water from the North Platte, Laramie, and Colorado Rivers to the South Platte. No action resulted from either study. During this era, the expanding political and economic influence of agri-business heightened the demand for water along the Front Range. Between 1890 and 1905, beet sugar factories owned by Great Western Sugar Company opened in Loveland and Greeley and two other smaller communities. The sugar beet crop increased the value of land in Weld, Larimer, and Morgan Counties, where most of the crop grew. Great Western Sugar eventually operated 11 of their 17 plants from the foot of the Rockies to the Colorado-Nebraska border.(3) In 1904, the newly established United States Reclamation Service (USRS) concluded a report which suggested raising the elevation of Grand Lake 20 feet. At the lake`s outlet, a dam would create a reservoir storing about 140,000 acre feet of water. The plan included construction of a 12-mile tunnel from Grand Lake to either the Big Thompson River or St. Vrain Creek. The report languished for years, but in the thoughts of many Northern Coloradans, its proposals were worth pursuing. Eleven years later, Congress passed a bill creating the 260,000-acre Rocky Mountain National Park, 50 miles northwest of Denver. That bill shaped the direction of future transmountain diversion in the area. The measure specifically granted permission for the USRS to `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.` On November 22, 1922, the federal Colorado River Compact apportioned the river`s water between the upper and lower basin states. Later in the decade, the Boulder Canyon Act provided funds for determining the amount of lands under irrigation in the Colorado River Basin. In the 1920s, as Washington regulated the Colorado`s future, the first summers of the Dust Bowl crossed the plains bringing heat and blowing soil to wither nearly $47 million in crops. The increasing ferocity of the weather convinced Colorado`s Democratic Senator, Alva B. Adams, to push the federal government for the adoption of a transmountain diversion project. The former banker from Pueblo, described as `on the conservative side,` endeavored to convince the `New Deal` administration of President Franklin D. Roosevelt that a mammoth water project would benefit not only the state`s agri-business, but its other local economies as well.(4) As Adams worked his way through the highest levels of bureaucracy in Washington, back on the high plains, some local citizens sought to attack the problem from a different angle. On August 14, 1933, a meeting between George M. Bull, Colorado engineer for the recently formed Public Works Administration (PWA) and the Commissioners of Weld County hashed over the feasibility of this public works venture. Those in the room saw the creation of a `Grand Lake` project as a counter-attack against the Depression. Locals claimed Weld County was the world`s largest area under irrigation, 4,022 square miles -- a region the size of Connecticut -- and in need of more water to further stimulate the agriculture-dominated economy. Soon, the plan was the center of discussion in Northern Colorado`s dusty town halls, clubs and lodges, and private offices. O.G. Edwards, president of the Greeley Chamber of Commerce, appointed a group known as the `Grand Lake Committee` in June 1933 to undertake surveys and solicit funding. By 1935, the committee had evolved into the Northern Colorado Water Users Association (NCWUA). Contributions to an expense fund poured in from Weld and neighboring Larimer Counties, the Greeley Chamber of Commerce, and private citizens. The NCWUA sought large companies with a big stake in the economic well-being of Northern Colorado: Great Western Sugar, the Union Pacific Railroad, and Burlington Railroad. These firms would benefit in some way after their investments to get the project off the ground. The expense fund`s first major expenditure went to hire two local engineers to prepare a report on the diversion potential of Grand Lake. Simultaneously, those private citizens with a taste for economic and civic activism decided to ask the PWA for a grant and a loan and try to get Reclamation interested in the project.(5) Every region desirous of Reclamation`s arrival always had one or two energetic representatives to issue invitations to the government to come and build, but few had as many resources as Charles Hansen. From 1902, until his death in 1953, Hansen was editor of the Greeley Tribune newspaper. A good deal of that career was spent fighting for transmountain diversion to the Colorado plains. Known as the `Godfather of the CBT` in his later role as president of the Northern Colorado Water Conservancy District (NCWCD), Hansen organized high plains farmers, businessmen, and local politicians to familiarize Reclamation and the federal government with the advantages of Northern Colorado. Hansen was an apostle of `quiet evangelism` as he coaxed all parties involved to support this work. One writer wooed by Hansen`s objectives stated, `He would talk in a low voice to anyone who would listen; then he would take you down in the basement of the Tribune and show you the worksheets, the preliminary drawings, the calculations. You would come away convinced that the CBT project would somehow, some day, come into being.` Hansen`s mission continued until the last days of his life, as he would come into theTribune offices and confer with conservancy district officials and his staff and `his questions to all were most frequently concerning the progress of the project.`(6) By the mid-1930s, progress toward the CBT was underway. The people of Northern Colorado, state government, and decision makers in the Federal government believed in the project, but backers were about to face opposition from an unexpected source. Similar to many Reclamation projects, the road to authorization for Colorado-Big Thompson was often regionalized and raucous, but unlike other projects, this battle was pitched, public, and an item of national debate. On January 21, 1935, a little publicized transaction occurred when the Public Works Administration (PWA) allotted Reclamation $150,000 to survey Grand Lake-Big Thompson. In early spring, W.C. Mendenhall, director of the U.S. Geological Survey, agreed to provide an impartial report on the Grand Lake proposal. In June, flamboyant Secretary of the Interior Harold L. Ickes asked the National Park Service if they had any apprehensions over beginning the Grand Lake project. The Park Service responded with a laundry list of worries over the future of Rocky Mountain National Park. A proposed covered conduit blocking park vistas, dumping rubble from the tunnel excavation inside the park and an overall decrease in park attendance troubled by construction, were the Park Service`s primary complaints. On July 3, putting their concerns to one side, Reclamation Commissioner Elwood Mead proceeded with a survey after an agreement was reached between his Bureau and the Park Service.(7) On October 7, 1935, U.S. Attorney General Homer S. Cummings ruled the Grand Lake venture was a `Government reclamation project,` and the Bureau of Reclamation now asserted permission to enter upon and use any area within the Rocky Mountain National Park necessary for the development of the project.(8) The following year, 1936, momentum for and against Grand Lake grew in both Colorado and Washington. On February 8, Porter J. Preston, Reclamation`s senior engineer in Denver, delivered a preliminary report containing an estimate of $43 million to complete the Grand Lake-Big Thompson Transmountain Project. Later that month, Park Service officials went on the record stating, `the National Park Service must take a position in opposition to this legislation because of the impairment to the Rocky Mountain National Park.` For most of 1936, the transmountain diversion project was under attack. The grassroots resistance to the proposed Grand Lake project was one of the few examples of natural resources activism between the Progressive Era and the ecology movement of the 1960 and 1970s. In March 1936, an avalanche of angry telegrams and letters buried Ickes` desk. Protests reaching Interior`s offices ranged from Western Slope newspapers, the National Lumber Manufacturers Association, the American Association for Advancement of Science, the National Association of Audubon Societies all the way to the Westchester County Conservation Association of White Plains, New York. In spite of Reclamation proposing both portals be located outside the park and promising minimal abuse to the natural surroundings, opponents strongly felt the park and Grand Lake would be ruined by construction and tunneling. Additionally, they feared wildlife would be harmed by fluctuation in Grand Lake. Ecologists accused the state, federal government, and Reclamation of conducting a "scheme of deception" to run the Grand Lake project past the American public.(9) Residents of Colorado`s western slope also opposed any plan that would remove their access to the Colorado River. To the casual observer, the sparsely populated region appeared to have little clout protesting the charge of a Federal bulldozer, but the `dean of the United States house of representatives,` Edward T. Taylor spoke as their voice. In congress since 1909, Taylor`s stature was such that he was known as Colorado`s `father of reclamation.` More importantly, he served as chairman of the powerful House Subcommittee on Interior Appropriations. Taylor sought acre-foot for acre-foot compensation for any water taken from the Colorado River. Representatives from eastern and western Colorado were locked in debate over a fair solution. Compromise eventually won out, as both sides an agreed to add a 152,000 acre-feet compensatory storage reservoir providing for existing and future Western Slope growth and development. The agreement would result in the Green Mountain Reservoir, 13 miles southeast of the town of Kremmling. The settlement, and a turn in opinion in favor of the project once the economic benefits of CBT were disseminated among the general public, won over this important man and group to the government's side.(10) Reclamation worked with local supporters and the NCWUA in an attempt to win the hearts of the public. Plaster models of the proposed works were exhibited across the United States and swayed public opinion and congressional appropriations. The miniature dams, reservoirs and tunnels illustrated the point that transmountain diversion would benefit Colorado with little damage to the park`s natural beauty. Leading the campaign Reclamation`s Chief Engineer R.F. Walter, suggested the name of the Grand Lake project change to prevent any further public antagonism. According to Walter, the name Grand Lake was, `to a certain class of people, like waving a red flag at a bull.` More a statement of purpose than a name change, Walter added, `The project is to divert the waters from the upper Colorado River into the Big Thompson River. It therefore seems consistent and it is recommended that the official name of the project be changed to Colorado-Big Thompson project.` Commissioner John Page agreed and the rechristening occurred on July 18, 1936.(11) The argument over CBT lingered for another year in the media and the executive and legislative branches of government. Loggerheads were broken on June 24, 1937, as the 75th Congress unanimously passed Senate Document 80, a plan of development and cost estimates. On August 9, Congress appropriated an initial $900,000 for CBT as part of Interior Department Appropriations Act in accordance with Senate Document No. 80. Congress may have given the green light to CBT, but there remained one final public discussion. On November 12, 1937, Ickes showcased all his rhetorical powers at a public hearing on CBT held in Washington, D.C. Succumbing to a touch of martyrdom, Ickes paternally requested peace between both departments, `Fortunately, or unfortunately, both the Reclamation Bureau and the Park Service are in the Department of the Interior -- and I love them both. . .It is largely a question of fact, it seems to me, whether the park would be adversely affected, or, if it should be affected, whether there could be any compensation for that.` Although Congress granted Reclamation authority to pursue CBT, the Secretary's opinion of the project was so well known during the hearings a headline on the front page of the November 12, Denver Post read: `Ickes Says He is Forced to Favor It.` Appealing to the conservationists, the former Chicago newspaperman turned environmental defender explained, `If I hold this project infeasible, I will probably go to the guillotine. If I should go to the guillotine, how many of you would go with me?`(12) Those willing to stand by Ickes on the scaffold included Sen. Adams, and Colorado`s Representatives in the House, Edward T. Taylor, Lawrence Lewis and Fred Cummings. Among those sharpening their blades during testimony were a Park Service spokesman who darkly predicted the project would be `the opening wedge which would eventually lead to destruction of the national park system.` Colorado`s pro-CBT newspapers described those speaking against the project as `Richly dressed women civic planners. . .landscape architects of national reputation and zealots.` One woman against CBT evoked a greater power than the federal bureaucracy when she thundered, `if God had wanted crops grown there (Northern Colorado) he would have provided the water to do it with.`(13) Construction was contingent on the development of a conservancy district to contract with the federal government. In 1937, the first step taken by the Colorado Legislature was passage of the Colorado Water Conservancy Law. In Colorado, a conservancy district can be organized by any district court by petition from a pre-arranged number of property owners. Land owners, and those who benefit from project development, must contribute to a project`s cost and operation in proportion to those benefits. The law provided that a district could hold property, levy taxes and assessments, allot water, and contract with the Federal government. An eleven member board, headed by Hansen as president, organized and met as the state`s first water district on September 28, 1937. The Northern Colorado Water Conservancy District would serve as the fortress against the controversies the CBT faced. The NCWCD covers 1.5 million acres of Colorado including almost all of Larimer, Boulder, and Weld Counties and portions of Morgan, Washington, Logan, and Sedgwick Counties.(14) On July 5, 1938, a contract agreement between the NCWCD and the federal government maintained the district had to repay half the estimated $44 million in construction authorized by the 1938 Interior Department Appropriation Bill. Under the Bill, the district`s maximum obligation is $25 million over a 40-year period and without interest. The contract also asked the NCWCD to pay for additional design features it requested to be built into the project but not covered by the original contract. The contract was amended to increase the District`s fixed construction obligation by $1,031,000, and $2.9 million additional revenues from water service preceding the start of repayment installments for applications against increases in the construction costs. The total fixed construction obligation, plus revenues from water rentals is $28.9 million. In 1957, the district took control of facilities integral to its project area and began its 40-year repayment schedule. The district paid fixed annual water rental charges through 1961, and made annual payments on construction charges for the ensuing 40 years. The district meets its obligation through water assessments and a one-mill ($1 on each $1,000) ad valorem tax on property in the district. The federal government assumed half of the costs, most repayed by power revenues.(15) Three important elements surrounding CBT`s authorization make it different from previous Reclamation projects. First, it provided supplemental water to existing farmlands and was not designed to reclaim uncultivated land. Second, water users were exempted in the project`s authorization law from the 160-acre per person limitation of the 1902 Reclamation Act. Northern Colorado`s agriculture was already in place and the amount of water each farmer received from CBT would not drastically increase the value of their properties. Finally, almost 50 percent of repayment costs would be liquidated by hydroelectric generation.(16) On December 21, 1937, President Roosevelt approved the findings of the feasibility study and work on CBT could now commence. In a Dec. 28, 1937, press release, Ickes commended those against CBT for conducting a `splendid fight to protect Rocky Mountain National Park.` The park`s defenders could take some solace from the final document Roosevelt signed. Reclamation agreed to abstain from construction within the park boundaries by running a diversion tunnel underneath the park. The east portal of the proposed tunnel would be 300 feet beyond the east boundary of the park while the west portal would be dug a quarter of a mile outside the western border. In addition, the Park Service had right of approval for any plans and specifications on lands scheduled to be added to the park, and the Park received both full electricity and a firm supply of water from CBT. On this agreement, Ickes pledged, `under my direction as Secretary of the Interior the interests of those devoted to the cause of our national parks will be protected.` After two years of personal involvement, Ickes may not have totally supported CBT, but he understood the first rule in the role of a bureaucrat -- follow orders from above.(17) On an unusually warm October 12, 1938, private engineers from around the country, Reclamation staffers, and other interested parties met in downtown Denver`s Customhouse to watch the opening of five bids on construction of the highest and largest earth-fill dam ever built by the Bureau. A little more than a month later in Washington, Ickes announced the first contract awarded to the Warner Construction Co. of Chicago on a low bid of $4,226,206.20. The contract covered the building of the Green Mountain Dam and power plant located on the Blue River. Warner had 1,620 days to complete the dam and power plant -- approximately May 1943. The design of the earth and rockfill dam called for it to stand 309 feet high with a crest of 1,150 feet and hold 4.5 million cubic yards of material. An adjoining reservoir would cover 2,000 acres and hold 152,000 acre-feet. Construction of Green Mountain Dam came first because of the agreement with Western Slope water users. Assuring water diverted to the fields and towns of Eastern Colorado would not impinge on Western Slope water rights, Green Mountain delivers 52,000 acre-feet a year to the Western Slope of Colorado.(18) On Dec. 1, 1938, perhaps as a result of the pre-construction media overkill, the Denver Post buried the story of the first official day`s work deep in its editions, while the other Denver daily, the Rocky Mountain News, did not bother to cover the story at all. Some work began two months earlier when Reclamation commenced preliminary clearing of a campsite and stringing of power lines from Dillon to the damsite. In that first winter in the mountains, Warner`s men completed the camp, moved in equipment, eventually boring the diversion tunnel for Green Mountain Dam. In May of 1940, the tunnel was completed as workers dug 150,000 yards of earth.(19) In spite of these hindrances, when the two headings met under the Continental Divide, the difference in alignment and grade closure could be covered by either a penny or a quarter, depending on whose measurement you believe. The accomplishments of these men is found in the impressive statistical record of their accomplishments. Breaking through the Divide required removal of 308,503 cubic yards of earth, and installation of more than 4.2 million pounds of steel and 124,411 cubic yards to line 13 miles of tunnel. Excavation from the east portal lasted 37? months with an average of 1,146 feet driven each month, while west portal contractors worked 31 months and averaged 833 feet per month. Through the tunnel, maximum flow could reach 550 cubic feet per second. East of the Adams Tunnel, the diverted water falls 2,900 feet as it flows through a series of tunnels, canals, powerplants and regulating reservoirs. Two fatalities occurred during 2.8 million man-hours of contract work on the tunnel.(33) The morning of June 23, 1947, signaled the close of the most arduous aspect of the project now respectfully nicknamed `Big Tom,` and the first of a series of ceremonial openings at each project feature. At 11:15 a.m., Colorado Governor Lee Knous pushed a button opening the west portal gate to water from Grand Lake. A crowd on the other side of the mountains mixed with dignitaries and dry-land farmers expected a rush of water, but instead saw an 18-inch wide stream emerge from the east portal a little after 2 o`clock that afternoon.(34) At a banquet in Loveland that evening, Reclamation Commissioner Michael W. Straus emphasized the importance of CBT in the future of Reclamation, `If it (CBT) fares well and fulfills its promise, the rest of the plans -- the plans that will move forward for almost a century in both the Missouri Basin and the Colorado Basin -- will proceed. If it fails, the plans will falter and the hopes of many of your neighbors will be dashed.`(35) Resulting from the war`s conclusion, construction materials and manpower were increasingly available. In spite of heavy snows, worked resumed in the autumn of 1949 on Granby Dikes 1, 2 and 4 and contracts were awarded for Granby Dam and Horsetooth Reservo After 1949, the construction on east side projects were in different states of completion. On September 4, 1947, the horseshoe-shaped Rams Horn Tunnel near Estes Park was finished. On July 14, 1948, Prospect Mountain Tunnel went into service followed by Spring Canyon Dam on August 11. October 1948 saw completion of three projects: Dixon Canyon Dam on the 19th, Marys Lake Dikes on the 20th, and Aspen Creek Siphon on October 30. The last major features of the decade, Solider Canyon and Horsetooth Dam, finished on July 20th and 21st, 1949. Both dams are on the perimeter of the 151,800 acre-feet capacity Horsetooth Reservoir. The reservoir is fed by the Horsetooth Section of the Horsetooth Feeder Canal. Soldier Canyon Dam is provided with an outlet with an outlet forming the Dixon Feeder Canal. The earth and rockfill dams are located in short, deep canyons which necessitated steep upstream and downstream slopes to contain the embankments within the canyon limits.(36) On September 23, Olympus Dam went into service. Olympus is an earth embankment dam with a concrete gravity type spillway section. The dam forms the 3,070 acre-feet capacity Lake Estes. It also serves as the afterbay for the Estes Powerplant and is used for re-regulation of canal flow and river control. In 1947, excavation began on four tunnels to provide flow from Lake Estes to Flatiron Reservoir: Olympus (1.8 miles), Pole Hill (5.4), Rattlesnake (1.7) and Bald Mountain (1.3). From Flatiron, water travels north to Horsetooth Reservoir and the Poudre River. Transporting the water is the Horsetooth Feeder Canal (renamed in 1956 the Charles Hansen Feeder Canal).(37) The canal crosses the Big Thompson Canyon about 1.5 miles upstream from the mouth of the Big Thompson River. The canyon is rugged with steep cliffs on both sides, and the canyon floor barely has enough room for the river and U.S. Highway 34. The canal crosses the river and highway in a 9-foot-diameter steel siphon. The siphon carries a capacity of 930 cfs to the Big Thompson River and 550 cfs to Horsetooth. A control structure ahead of the siphon provides water for irrigation to the Big Thompson River. It also bypasses surplus water and releases flow to the Big Thompson Powerplant, nine miles west of Loveland. A supply conduit diverts water one mile upstream from the Big Thompson River from the control structure and transfers it by tunnel to the Hansen Feeder Canal. The water provides generation at the power plant, supplies users in the Big Thompson Valley, or is stored in Horsetooth Reservoir. North of the Big Thompson River the canal passes through four concrete-lined tunnels, and the outlet of the last tunnel discharges water into the Horsetooth Reservoir. In 1949, work started on the canal and completed in 1953.(38) In 1947, work advanced on the Estes Park Aqueduct and power system. Beginning at the east portal of the Adams Tunnel, a 1.3 mile buried siphon carries water to Aspen Creek and then on to the Rams Horn Tunnel. Out of the tunnel, water flows through a short pipeline, or penstock, to the Marys Lake Dikes 1 and 2 and reservoir, all located 2.5 miles from Estes Park. The reservoir created by these dikes is the afterbay for the Marys Lake Power Plant. Past Marys Lake, water travels through a 3,143 foot conduit to the Prospect Mountain Tunnel. The conduit`s inlet structure is submerged five feet below the minimum reservoir elevation to avoid ice build-up. In June 1949, the aqueduct and power system was completed. Pole Hill Diversion and Afterbay Dams are earth and rockfill structures at the Estes Park Aqueduct, 10.5 miles east of Estes Park. Pole Hill Diversion Dam directs the flow of Little Hell Creek away from the Pole Hill Powerplant toward Rattlesnake Tunnel and Reservoir. Pole Hill Afterbay Dam contains a siphon spillway and outlet creating the headworks for Rattlesnake Tunnel conduit leading to Rattlesnake Powerplant. In 1952, construction on Pole Hill began and completed a year later. Built of earth and rockfill, Rattlesnake Dam, provides an additional afterbay for Pole Hill Powerplant and a forebay for Flatiron Powerplant. The dam is 12 miles east of Estes Park and first stored water in 1954. The Flatiron Afterbay Dam is an earth and rockfill structure located on Chimney Hollow Creek eight miles southwest of Loveland. The reservoir created by the dam is the afterbay of the Flatiron Powerplant.(39) In July 1951, the last dedication of a major west slope fixture took place at the north end of Lake Granby. The Granby Pump Plant generated power by passing water through the Estes Park Power Plant turbines, delivered back through the Adams Tunnel transmission line. The structure had been completed in 1949, but installation of pumps, motors and hydraulic pipelines and testing took two years. At completion, Granby Pump Plant stood sixteen stories high, although on only three stories are visible above ground. Commissioner Straus, back in Colorado for another ceremony, visualized Granby`s pumps as the `beating heart` and the Adams Tunnel the `jugular vein` of the CBT energizing the entire state of Colorado.(40) Over a twenty year period, construction took place on many fronts in Colorado. Those who manned the equipment, dug the tunnels, and set the dynamite, saw their wages increase and went about their jobs in relative safety. In 1940, contract employees made 83 cents an hour while government employees received 85 cents an hour. Pay grew gradually from $1.84 an hour in 1947 to $2.23 an hour in 1953. A two month strike in the spring of 1949 and a month long shutdown in May 1950 were the only periods of labor trouble during the post-Adams Tunnel era. Through the summers of 1947 to 1951, there was work for a thousand men, and then the number of employees would drop to around 800 in winter. There were some fatalities among those working to bring water over the mountains. Four men died in 1948, two in 1949, and an additional three in 1950. These accidental deaths resulted from cave-ins, machinery malfunction, electrocution, and a tractor rolling over and crushing its operator.(41) By the mid-1950s, Reclamation could look back at almost twenty years of sustained achievement. Their work resulted in 13 dams and 10 reservoirs storing a total capacity of 994,340 acre feet of moisture. Power generation supplies an additional 18 pumping plants and 11 powerplants. Following is a list of the capacities and dimensions of the Reclamation designed dams and reservoirs of the Colorado-Big Thompson Project: Table I Sustained by `Elaborate models of flumes, surge tanks, canals and dams,` Reclamation successfully built a `cadillac system` designed to resist Colorado`s winters, summers, floods, and droughts. The `machine` soon paid dividends in the mid-50s, when Colorado`s weather deviated from moderate seasons into a cycle of dry, arid weather, presenting the completed project`s with its first significant challenge.(42) (Source: U.S., Department of Interior, Bureau of Reclamation, Colorado-Big Thompson Project Technical Record of Design Construction, Vol. 2, (Washington, D.C.: Government Printing Office, 1957), vi.

Plan

The project diverts approximately 260,000 acre-feet of water annually (310,000 acre-feet maximum) from the Colorado River headwaters on the western slope to the Big Thompson River, a South Platte River tributary on the eastern slope, for distribution to project lands and communities. The Northern Colorado Water Conservancy District apportions the water used for irrigation to more than 120 ditches and 60 reservoirs. Eleven communities receive municipal and industrial water from the project. Electric power produced by six powerplants is marketed by the Western 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 water to the Alva B. Adams Tunnel for diversion under the Continental Divide. To assure irrigation and power generation under prior rights on the Colorado River, Green Mountain Reservoir was constructed on the Blue River. Spring runoff is stored in this reservoir and later released to meet the requirements of the Colorado River, and to allow diversion of water by the project throughout the year. Irrigation systems on the Colorado River, above the Blue River confluence, were improved to enable continued use of existing rights. Releases are made from Lake Granby to maintain the Colorado River as a fine fishing stream. The principal storage features are Lake Granby and Granby Dam, located on the Colorado River near Granby. Willow Creek, a tributary below Lake Granby, is diverted by Willow Creek Dam and Canal. Willow Creek Pumping Plant lifts the water 175 feet; it then flows by gravity to Lake Granby. Granby Pumping Plant lifts the water 125 feet from Lake Granby to Granby Pump Canal. The canal conveys the water 1.8 miles to Shadow Mountain Lake, which also intercepts North Fork flows of the Colorado River. Shadow Mountain Lake connects with Grand Lake to make a single body of water from which diversions flow to the Alva B. Adams Tunnel to begin the journey to the eastern slope. Emerging from Alva B. Adams Tunnel into the East Portal Reservoir, the water flows across Aspen Creek Valley in a siphon and then under Rams Horn Mountain through a tunnel. At this point, it enters a steel penstock and falls 205 feet to Marys Lake Powerplant. This powerplant is located on the west shore of Marys Lake, which provides afterbay and forebay capacity for reregulating the flow. Between Marys Lake and Estes Powerplant, on the shore of Lake Estes, the water is conveyed by Prospect Mountain Conduit and Prospect Mountain Tunnel. Lake Estes, below Estes Powerplant, is formed by Olympus Dam constructed across the Big Thompson River. The afterbay storage in Lake Estes and the forebay storage in Marys Lake enable the Estes Powerplant to meet daily variations in energy demand. Water from Lake Estes and some Big Thompson River floodwaters are conveyed by Olympus Siphon and Tunnel and Pole Hill Tunnel and Canal to a penstock through which the water drops 815 feet to Pole Hill Powerplant. It is then routed through Pole Hill Powerplant Afterbay, Rattlesnake Tunnel, Pinewood Lake, and Bald Mountain Pressure Tunnel, and dropped 1,055 feet through two penstocks to Flatiron Powerplant. This powerplant discharges into Flatiron Reservoir, which regulates the water for release to the foothills storage and distribution system. The afterbay storage in Flatiron Reservoir and the forebay storage in Pinewood Lake enable Flatiron Powerplant to meet daily power loads. Southward, the Flatiron reversible pump lifts water from Flatiron Reservoir, a maximum of 297 feet and delivers it through Carter Lake Pressure Conduit and Tunnel to Carter Lake. When the flow is reversed, the unit acts as a turbine-generator and produces electric energy. The St. Vrain Supply Canal delivers water from Carter Lake to the Little Thompson River, St. Vrain Creek, and the Boulder Creek Supply Canal. The latter delivers water to Boulder Creek and Boulder Reservoir. The South Platte Supply Canal, diverting from Boulder Creek, delivers water to the South Platte River. Northward, the Charles Hansen Feeder Canal transports water from Flatiron Reservoir to the Big Thompson River and Horsetooth Reservoir. The canal crosses the Big Thompson River in a siphon above the river and highway. Water from the Big Thompson River can be diverted into the canal by Tunnel No.1, Horsetooth Supply Conduit. Project water deliveries and Big Thompson River water to be returned to the river are dropped through a chute from the feeder canal ahead of the siphon crossing, or are passed through the Big Thompson Powerplant to convert the available head to electric energy. Horsetooth Reservoir is west of Fort Collins between two hogback ridges, where Horsetooth Dam closes the gap at one end. Soldier, Dixon, and Spring Canyon Dams and Satanka Dike close the remaining gaps. An outlet at Soldier Canyon Dam supplies water to Fort Collins, rural water districts, Colorado State University, and the Dixon Feeder Canal for the irrigated area cut off from its water supply by the reservoir. The principal outlet from Horsetooth Reservoir is through Horsetooth Dam into the Charles Hansen Canal. This canal delivers water to a chute discharging into the Cache la Poudre River and to a siphon crossing the river to supply the Poudre Valley and Reservoir Company Canal. A turnout supplies the Greeley municipal water works. Water is delivered to the river to replace, by exchange, that water diverted upstream of the North Poudre Supply Canal, which conveys it to the North Poudre Ditch. Green Mountain Dam is on the western slope 13 miles southeast of Kremmling on the Blue River, a tributary of the Colorado. This dam provides replacement storage for water diverted by the project to the eastern slope. The dam is an earthfill structure, 309 feet high, with a crest length of 1,150 feet and a volume of 4,360,211 cubic yards. The reservoir has a total capacity of 153,639 acre-feet. The powerplant has two units with a total installed generating capacity of 21,600 kilowatts. Granby Dam and Lake Granby Granby Dam is located on the Colorado River about 5.5 miles northeast of Granby. It collects and stores most of the project water supply, including the flow of the Colorado River and water pumped from Willow Creek. The dam is constructed of compacted earthfill, 298 feet high, with a crest length of 861 feet. There are 12,722 feet of auxiliary dikes. The reservoir has a capacity of 539,800 acre-feet. Total volume of the dam is 2,974,000 cubic yards. The dikes have a total volume of 1,739,000 cubic yards. Willow Creek Dam, Reservoir, and Pumping Plant Willow Creek Dam is 127 feet high, 1,100 feet long, and constructed of earthfill. There are 3.4 miles of canals with a capacity of 400 cubic feet per second and a pumping plant with two 200-cubic-foot-per-second pumps that lift water 175 feet into Lake Granby. The dam diverts an average of 40,000 acre-feet of water each year from Willow Creek into Lake Granby. The reservoir capacity is 10,600 acre-feet. Water is pumped from Lake Granby into Shadow Mountain Lake by Granby Pumping Plant and Canal. The pumping plant contains three centrifugal pumps with a total capacity of 600 cubic feet per second at 186-foot head. The pumping lift ranges from 85 to 186 feet according to the water surface elevation in Lake Granby. The water is discharged into a canal which has a capacity of 1,100 cubic feet per second, and conveyed 1.8 miles to Shadow Mountain Lake. Shadow Mountain Dam and Reservoir Shadow Mountain Dam, located on the Colorado River below its confluence with the Grand Lake outlet, is an earthfill structure 63 feet high and 3,077 feet long. The reservoir formed by the dam has a total capacity of 18,400 acre-feet and is linked to Grand Lake through a connecting channel. Shadow Mountain Lake receives the water pumped from Lake Granby and also intercepts North Fork flows of the Colorado River. Project water is released from Grand Lake directly into the Alva B. Adams Tunnel, through which it flows to the eastern slope of the Continental Divide. This 9.75-foot-diameter, 13-mile-long tunnel extends from Grand Lake through the Continental Divide to a point 4.5 miles southwest of Estes Park. It has a capacity of 550 cubic feet per second. The structures of this system convey water 4.3 miles from the east portal of Alva B. Adams Tunnel to the Big Thompson River. Emerging from the tunnel into the East Portal Reservoir, the water flows across Aspen Creek Valley in a siphon and then under Rams Horn Mountain in a tunnel. At this point, the water enters a steel penstock and falls 205 feet to Marys Lake Powerplant, which has an installed capacity of 8,100 kilowatts. This plant is located on the west shore of Marys Lake, which has been enlarged by diking the small natural basin to provide afterbay and forebay capacity for reregulating the flow. From Marys Lake to Estes Powerplant, the water is dropped 482 feet in a pressure system consisting of Prospect Mountain Conduit and Prospect Mountain Tunnel. Estes Powerplant contains three generating units served by three 78-inch-diameter penstocks about 0.75 mile long. The installed plant capacity is 45,000 kilowatts when operating under an average net head of 482 feet. Olympus Dam, a zoned earthfill structure with a concrete overflow spillway, is 70 feet high and has a crest length of 1,951 feet. It impounds Lake Estes on the Big Thompson River and provides regulating capacity for energy purposes. The lake has a total capacity of about 3,100 acre-feet and controls the discharges from Estes Powerplant, river inflow and outflow, and releases of project water to the Lower East Slope Power System. This system conveys project water from Lake Estes in a southeasterly direction to the Foothills storage and supply system. Project water released from Lake Estes flows through Olympus Siphon and Tunnel and Pole Hill Tunnel and Canal into Pole Hill Penstock and Powerplant. Water also can be released from Lake Estes to the Big Thompson River. Leaving Pole Hill Powerplant Afterbay, the water enters Rattlesnake Tunnel and flows into Pinewood Lake formed by Rattlesnake Dam. Bald Mountain Tunnel carries the water into the Flatiron Penstocks and Powerplant which discharges into Flatiron Reservoir, where it is stored for irrigation use. Pole Hill Powerplant operates under an average net head of 815 feet with a generating capacity of 33,250 kilowatts. The Flatiron Powerplant operates under an average net head of 1,055 feet, with a generating capacity of 71,500 kilowatts. The powerplant contains two main power units and a reversible 13,000-horsepower pump-turbine unit which lifts water southward from Flatiron Reservoir to Carter Lake. This unit is capable of discharging a maximum of 370 cubic feet per second into Carter Lake and normally operates on surplus or off-peak power generated by other power units of the project system. The pumping unit at Flatiron Powerplant pumps from Flatiron Reservoir to Carter Lake through a 1.4-mile-long connecting pressure tunnel. The pumping lift through this tunnel ranges from 200 to 300 feet, depending on the water surface elevation in Carter Lake. During peak load demands on the project system, water can be released from Carter Lake to flow back into Flatiron Reservoir, and at such times the pump-turbine operates in reverse to generate 8,500 kilowatts of power. Flatiron Dam provides afterbay storage for water discharged from the powerplant. The water then flows by gravity northward through the Charles Hansen Feeder Canal, to and across the Big Thompson River, and on to Horsetooth Reservoir for delivery to the Poudre River, Poudre Valley Canal, and, by exchange, to the North Poudre Supply Canal Water pumped southward into Carter Lake is stored for irrigation deliveries to the Little Thompson River, St. Vrain Creek, Boulder Creek, and the South Platte River. Carter Lake Dam and Reservoir Carter Lake is one of the two main project storage reservoirs in the East Slope distribution system. Water is stored in this reservoir for delivery to the Little Thompson River, St. Vrain Creek, Boulder Creek, and the South Platte River, for return to Flatiron Reservoir for use in the Big Thompson or Cache la Poudre Valleys, or for power generation. Carter Lake Reservoir is formed in a natural basin in the foothills by a 214-foot-high earthfill dam and two smaller dams across low saddles in the surrounding hills. The reservoir has a total capacity of 112,230 acre-feet. Leading from the Carter Lake outlet, the St. Vrain Supply Canal extends southward 9.8 miles to St. Vrain Creek near Lyons. It consists of an open canal, siphons, tunnels, drops, and flumes designed to convey 625 cubic feet per second of water to the Little Thompson River turnout and 575 cubic feet per second from the turnout to St. Vrain Creek. Boulder Creek Supply Canal begins at the turnout near the end of the St. Vrain Supply Canal, crosses St. Vrain Creek by a siphon, and extends southeasterly 15.7 miles It discharges into Boulder Creek about 6 miles east of Boulder. The canal has a carrying capacity of 200 cubic feet per second. Near the lower end of the canal, the city of Boulder constructed Boulder Reservoir to be used for storage and regulation of the city`s water for replacement water carried in the canal. This reservoir was built under an agreement between the city and the Northern Colorado Water Conservancy District. Under the agreement, the reservoir provides 175 cubic feet per second of flow for the South Platte Supply Canal. This canal extends from Boulder Creek generally north-east to the South Platte River, a distance of about 32.2 miles. The capacity of the canal is 230 cubic feet per second at the start and progressively decreases. Near the lower end of the canal, the Platte Valley Irrigation Co. constructed Coal Ridge Waste Lake for storage. This reservoir was built under an agreement with the Northern Colorado Water Conservancy District. Under the agreement, the lake provides 100 cubic feet per second of South Platte Supply Canal flows. Beginning at the outlet of Flatiron Reservoir, the Charles Hansen Feeder Canal extends northward to Horsetooth Reservoir. The canal has a capacity of 930 cubic feet per second to the Big Thompson River and 550 cubic feet per second to the reservoir. The canal crosses the Big Thompson River and U.S. Highway 34 in a 9-foot-diameter steel siphon. A control structure ahead of the Big Thompson River Siphon provides a means to release irrigation water to the Big Thompson River to bypass surplus water, and to release water to the Big Thompson Powerplant. The Horsetooth Supply Conduit, an important feature of the canal, diverts water from the Big Thompson River about 1 mile upstream from the control structure and delivers it via a tunnel to the Charles Hansen Feeder Canal above the control structure. Diverted water is used for power generation at the Big Thompson Powerplant, or water surplus to the needs of the Big Thompson Valley can be stored in Horsetooth Reservoir. North of the Big Thompson River, the canal passes through four concrete-lined tunnels; the outlet of the last tunnel discharges the water into the Horsetooth Reservoir. The Big Thompson Powerplant is on the Big Thompson River about 9 miles west of Loveland and just downstream from the river crossing of the Charles Hansen Feeder Canal. The plant operates under an effective head of 180 feet and has a generating capacity of Horsetooth Reservoir, with a total capacity of about 151,750 acre-feet, furnishes the main supply for the Poudre Valley, where 50 percent of the project water is used. The reservoir is 6.5 miles long, and is formed by four large earthfill dams. Horsetooth Dam closes the northern end of the valley, and Soldier Canyon, Dixon Canyon, and Spring Canyon Dams close natural outlets eroded through the hogback ridge. These dams have heights of 155, 226, 240, and 220 feet, respectively. The dams contain more than 10 million cubic yards of earthfill. Outlets at Horsetooth Dam discharge into the Charles Hansen Canal, which is designed to carry a maximum of 1,500 cubic feet per second northward 5.1 miles to the Cache la Poudre River. Project water released into the river at this point is used to supplement the water supply of irrigation systems stemming from the river. It also serves as replenishment for the water taken from the river a few miles upstream by the North Poudre Supply Canal, a 12.5-mile-long canal which carries supplemental water to the North Poudre Ditch. The 0.5-mile, 250-cubic-foot-per-second Windsor Extension Canal takes part of the Poudre supply across the river to the Poudre Valley Canal, an older waterway that serves a portion of the conservancy district. The Soldier Canyon Dam outlet supplies water to Colorado State University, to the small Dixon Feeder Canal for the irrigated area cut off from its water supply by Horsetooth Reservoir, to Fort Collins, and to rural water districts. The Cache la Poudre, Big Thompson, and Little Thompson Rivers, and St. Vrain and Boulder Creeks are tributaries of the South Platte River, through which water imported from the western slope is supplied to the South Platte River Basin system. This supplemental water is used to alleviate the critical shortages that have hampered and restricted the cultivation of fertile lands in the South Platte River Valley. Power transmission facilities include nearly 677 miles of transmission lines, 35 permanent substations, 2 mobile substations, 1 mobile transformer, 22 metering stations, and 6 permanent service shops. With the exception of 3 miles of steel tower construction and 13.1 miles of submarine-type conduit, the transmission circuits are of wood pole H-frame construction. The submarine-type conduit is the connection between eastern and western slope circuits and is in a nitrogen gas-filled pipe suspended from the top of the Alva B. Adams Tunnel. Project power facilities are interconnected with plants of the North Platte, Kendrick, Riverton, and Shoshone Projects, and are tied into the lines of the Public Service Company of Colorado at five different locations in Colorado. Most of these power features were transferred to the Department of Energy`s (DOE) Western Area Power Administration upon the creation of DOE in 1977. The Bureau of Reclamation operates all project features on the western slope, including power, storage, and carriage, and all similar works on the eastern slope above the supply canals leading from Carter Lake and Horsetooth Reservoirs. All project works below these two reservoirs are operated and maintained by the Northern Colorado Water Conservancy District.

Contact

Title: Area Office Manager
Organization: Eastern Colorado Area Office
Address: 11056 W. County Rd 18E
City: Loveland, CO 80537-9711
Fax: 970-663-3212
Phone: 970-667-4410

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Title: Public Affairs Officer
Organization: Great Plains Region
Address: 2021 4th Avenue North
City: Billings, MT 59101
Fax: 406-247-7604
Phone: 406-247-7610

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Organization: Colorado River Water Conservation District
Address: PO Box 1120
City: Glenwood Springs, CO 81602
Phone: 970-945-8522

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Organization: Copper Mountain Resort
Address: PO Box 3001
City: Copper Mountain, CO 80443
Phone: 970-968-2882

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Organization: Estes Park, Town of
Address: PO Box 1200
City: Estes Park, CO 80517
Phone: 970-586-5331

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Organization: Hamilton Creek Metropolitan District
Address: PO Box 4378
City: Breckenridge, CO 80424
Phone: 970-453-2734

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Organization: L G Everist, Inc
Address: PO Box 1150
City: Silverthorne, CO 80498
Phone: 970-468-2021

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Organization: Northern Colorado Water Conservancy District
Address: PO Box 679
City: Loveland, CO 80539
Phone: 970-667-2437

PROJECTS & FACILITIES

Colorado-Big Thompson Project

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