Generating electricity since 1909
Once aptly named the Grand River, the Colorado has been a lifeline for humans as long as they have lived in the high country. It gave humans a way west – sometimes the only way – as they followed its path through the mountains. It was also a rich untapped resource for the early settlers of western Colorado. And not just to water crops. Shortly after it became a town in the mid-1880s, Glenwood Springs had electric lights, thanks to a hydroelectric plant constructed in 1886 near the Vapor Caves.In 1904 a visionary businessman, Myron T. Herrick, hatched a plan to link hydro plants across the Western Slope to carry electricity through a network of transmission lines to the booming city of Denver. The burgeoning city was a ready market since its population had almost doubled between 1890 and 1905.Herrick and five investors formed the Central Colorado Power Co. and launched their ambitious plan; however, only two plants were completed, Shoshone and Boulder Canyon.Herrick’s star was not dimmed by the failure of his grand plan, however. He went on to become governor of Ohio and ambassador to France.Construction of the two-mile-long diversion tunnel that would bring water from the Colorado River to the plant began in 1907, and the plant went into operation in 1909.On Sept. 3, 1924, the Colorado Power Co., which had merged with Leadville Light and Power in 1913 and acquired other power companies over the years, merged with Public Service Co. of Colorado (PSC). Shoshone then became part of PSC’s extensive network of electrical generating plants and transmission lines. Today Shoshone is operated by PSC and Xcel Energy.
People have been harnessing the power of water to run machines far back into history. Water wheels were used to grind wheat by the Romans and were used through the Middle Ages. In the 19th century they powered textile mills and generated electricity. Today, hydro is the source of about 20 percent of the world’s electricity.Electrical generation with water power is a simple process. Generally, water falls with great force down large pipes called penstocks, which direct the water into turbines. The force of the water turns the propeller-like turbines, and the rotation of the turbine shaft in turn spins the generators, which produce electrical current. Once the water flows through the turbine it returns to the river.The amount of electricity generated is directly related to the force of the water as it flows into the turbine, also called the “head,” and the volume of the river.At Shoshone, a 7-foot high, 245-foot long dam on the Colorado River impounds the water, some of which is diverted into a tunnel high above the plants. The tunnel, at 12 feet high and 16 feet, eight inches wide, carries water at a flow rate of 1,408 cubic feet per second a little over two miles from the dam to the plant. The water drops 287 feet to the plant through twin, 9-foot diameter penstocks, which feed the water into the plant’s two turbines. The two 9,000-horse power hydraulic turbines turn at 400 revolutions per second and drive two 7,200-kilowatt, 4,000-volt generators. “We run one turbine in the winter and do maintenance on the other,” Verdieck said. He keeps a constant eye on the levels of the dam, which is measured at its current elevation above sea level.”That’s the fun part this time of year. We run at less capacity,” he said. The river presents a challenge because its levels fluctuate and the men at the plant have to let water out of the dam to keep the flow volume constant in the tunnel.The 4,000 volts produced by the generators are “stepped up,” said mechanical foreman Gary Verdieck, by five transformers in a substation just above the plant to 115,000 volts before the electricity enters the transmission line.Water volume through the plant varies by season and year. The greatest amount of water volume measured in the Colorado River at the plant was 30,100 cubic feet per second in June 1918. The lowest peak – 2,064 cfs – was in 2002.Shoshone’s power feeds into electrical transmission lines. A 115 kV line, installed during the original construction of the plant, was an impressive engineering feat for its day. It runs across three mountain passes at altitudes above 12,000 feet to Denver, a total of 153.2 miles. A 69 kV line runs through Glenwood Springs to Rifle, and a 13 kV line provides power to the Shoshone Dam and the Grizzly Creek Rest Area on Interstate 70.
While much of the plant’s original equipment is still in operation, the plant is now almost completely automated. On a fresh fall day in mid-September, Verdieck spoke with pride about Shoshone’s ease of operation. In a small room within the plant with the turbines roaring on the other side of the glass wall, command central is a computer atop a small desk. That and the electrical circuitry hidden behind a metal cabinet are the heart of the operation.When Verdieck started his career at Shoshone in the mid-1980s, there were 16 people manning the plant. Work at Shoshone runs in the family. Verdieck’s father and two uncles worked in the plant before him.Now there is a crew of six with two or three working at any one time. In fact, when the men are off duty, control of the plant switches to an Xcel hydro plant called Cabin Creek above Georgetown.”There are cameras on the building and on the dam, and they can watch them from Cabin Creek,” Verdieck explained. Cabin Creek operates 24 hours a day, seven days a week.But the real work, as it has been for all the 97 years Shoshone has been in operation, is keeping the machines in working order. Verdieck will do everything from crawling into one of the turbines for routine maintenance, to welding to running one of the plant’s World War II vintage – but functional – lathes to fabricate a part.”The electricians call us (mechanics) the Maytag guys,” he quipped, for the jack-of-all-trades skills necessary to keep the equipment working smoothly.
Shoshone has the most powerful and senior water right on the Colorado River. The right dates to 1902 and amounts to 1,408 cubic feet per second (cfs), including a 1940 right for 158 cfs. Shoshone’s water use is non-consumptive because it returns all of the water it diverts back into the river. Today it supplies power to about 16,700 homes in the Roaring Fork Valley, New Castle, Silt, Rifle and the Front Range.During low flows, because it has the most senior right on the river, it is allowed to divert the entire river into its turbines, according to Chrissy Sloan, a research fellow with the Roaring Fork Conservancy, who prepared a government report about Shoshone and Colorado River flows in 2004 and who is now a practicing water attorney.Another senior and powerful call on the river is a collection of irrigation water rights collectively called the Cameo call. Dating back to 1908, the calls supply water to the orchards and truck farms, as well as a power plant in the Grand Valley near Grand Junction. The call operates typically during the irrigation season between April and October. But despite how wet or dry a year it is, the call comes on every year because the river does not have enough water to satisfy all its water rights, as well as the demands of the downstream states.
An historic tug-of-war between Front Range municipalities who need West Slope water and West Slope ranchers, recreationists and other users who are protective of their stretch of the Colorado, came to a head earlier this year when Xcel Energy and Denver Water announced they would renew a utility agreement that includes provisions for Shoshone’s water use. The agreement, which was originally inked in 1986, calls for Xcel to release part of the water it uses to run the plant enabling Denver to store more water in its West Slope reservoirs.Under the new agreement, which is set to be signed in January, Xcel would not give up its Shoshone water rights, but would take less water out of the river than it is entitled to. Denver in turn, would have a chance to fill up its reservoirs, including Wolford near Kremmling and Dillon Reservoir, during spring runoff. The call would be relaxed from Mar. 20 to May 20.Also as part of the agreement, Xcel would relax its right and curtail the flow into the plant only during times of water shortage, when reservoirs were less than 80 percent full by July 1 and runoff is predicted to be 85 percent below normal.That condition has taken place only once since the agreement was forged in 1986. In 2003, as a response to severe drought and low flows in the river, Xcel agreed to relax its Shoshone call and let Denver use the freed water to fill its West Slope reservoirs. Denver also agreed to compensate Xcel for any loss of electricity due to a lack of water to drive the turbines.The new agreement calls for a potentially longer curtailment of Shoshone’s water use. Xcel would agree to a longer period of relaxation of its water use, “When water supplies are more severely impacted … if such longer period is defined cooperatively between the (Denver Water) Board, (Xcel) and appropriate West Slope entities,” according to the wording of the new agreement.This new wrinkle in the Denver Water/Xcel agreement, indeed the entire agreement itself, has not sat well with some who are now involved in a series of Colorado River Roundtable meetings. The meetings are part of a state initiative to bring together water stakeholders – water providers, ranchers, farmers, recreationists and local governments, to name a few – in the state’s nine river basins, to make critical decisions about future water needs in a period of unprecedented growth.Concurrent with the state discussions is an effort to forge a new agreement between the seven states along the Colorado River to better allocate the diminishing resources of the river. Allocations of water for each of the seven states through which the river flows – Colorado, Utah, Wyoming, New Mexico, Arizona, Nevada and California – were cast in stone in the Interstate Compact of 1922. The compact essentially requires the upper basin states to deliver a fixed amount of water annually to the lower basin states. The problem now, 84 years later, is there isn’t enough water in the river to meet those obligations.Local engineer Louis Meyer voiced the fear of many on the West Slope at a roundtable meeting this summer that the agreement between Denver Water and Xcel was “turning the spigot on and once it was on it wouldn’t be shut.”Meyer, who consults with local municipalities on their water treatment plants, has said that a reduction in the river’s flows would degrade the quality of water in Rifle’s treatment plant, which cannot handle the increased dissolved solids and minerals.Perhaps even more telling, in 2005 Gov. Bill Owens signed House Bill 1177, called the Colorado Water for the 21st Century Act, which declared that the Colorado River is not an unlimited resource. The same legislation paved the way for the roundtable discussions which are now taking place across the state.The most critical question facing the state today is just how the cities of the Front Range will supply water to their growing populations. Except for very wet years, demands on the river’s water exceed the available supply and therefore it’s certain Shoshone’s future water use will be under intense scrutiny by many on the West Slope as time goes on.
Contact Donna Gray: 945-8515, ext. firstname.lastname@example.org
Support Local Journalism
Support Local Journalism
Readers around Glenwood Springs and Garfield County make the Post Independent’s work possible. Your financial contribution supports our efforts to deliver quality, locally relevant journalism.
Now more than ever, your support is critical to help us keep our community informed about the evolving coronavirus pandemic and the impact it is having locally. Every contribution, however large or small, will make a difference.
Each donation will be used exclusively for the development and creation of increased news coverage.
Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.
User Legend: Moderator Trusted User
Bears senior Bryce Rowly picked up a quarterback sack nearly midway through the first quarter. The next play, with Salida deep in their own zone and desperate for yards, junior Broc Caldwell intercepted a pass…