| One wall of the old Mammoth Dam still stands and seems to balance the late afternoon moon on the end of a piece of rebar. The collapse of the structure in 1917 sent billions of gallons of water from the reservoir into Gooseberry Creek and down the canyon into the Price River. |
In June 1917, people working in the Gooseberry Narrows about 12 miles east of Fairview noticed water leaking from the base of Mammoth Dam.
The warning traveled down the canyon while the Price Irrigation Company employees tried to release water from the nearly constructed reservoir and plug the leak.
But the crews could not halt the effects of a poor design and inadequate engineering safeguards and the dam collapsed the afternoon of June 25. Approximately 3.6 billion gallons ran down Gooseberry into Fish Creek, then into the Price River, where the water wreaked havoc in Castle Gate and Helper on the way to the Green River.
The damage was extensive, with coal operations curtailed in Castle Gate due to an inoperable Denver & Rio Grande track system damaged by water.
The time that passed between the leaks being detected and the breakage of the dam was more than 24 hours.
Many people residing along the course of the river had been warned and the damage was somewhat diminished.
The incident was cited as causing one death, which occurred after a woman backed a car into the river after examining the flood’s path.
Following the disaster, some people claimed the collapse was sabotage. They accused everyone from jealous Sanpete County residents who thought the water should be theirs to German spies. The United States had entered World War I against Germany two months before the dam collapsed.
In the end, an enquiry into the dam’s demise by a commission set up by Utah Gov. Simon Bamberger determined the failure was due to an engineering problem.
The dam was never rebuilt, but the structure’s design, construction and demise are part of the struggle of western water users.
In particular, the Mammoth Dam concept and disaster play a role in the conflict that has raged for more than 100 years between Sanpete and Carbon County regarding water from the Gooseberry drainage.
The history of the ongoing struggle is a difficult story to compile, primarily because the accounts vary and many records have been lost.
But basically, Sanpete residents believe that all water and snowfall in the county belong to them. The fact that all water on the eastern slope of the mountains that edge the Sanpete Valley has a natural drainage into the Price River system simply does not matter to the residents.
The idea of building a dam in the Gooseberry drainage goes back many years before the turn of the 20th century.
But the first recorded documentation of work toward the project was filed with the Sanpete County Recorder’s Office in 1895.
The document was a survey for a right-of-way submitted by Charles S. Stevenson. The hydraulic and irrigation engineer had completed the survey for a group of interested parties, eight Sanpete residents and one man from Carbon County, George Frandsen.
Stevenson’s survey started on June 23 and ended July 3, 1895. The document was filed with the recorder’s office on Aug. 7, 1895. The engineering study identified an area of approximately “926 acres on unimproved land” where the reservoir could be constructed.
Construction on the reservoir project would eventually proceed, but not under the tutelage of the originators, although they filed on the water in 1896 under the name of the Mammoth Reservoir Company.
In 1900, little work had been done toward the construction of the dam and several Sanpete farmers gained the rights to the future reservoir.
The agriculture producers from Sanpete County intended to divert water through the mountain into the Fairview-Mount Pleasant area, but lacked adequate financing to tackle the endeavor.
The project was subsequently presented to the Irrigated Land Company.
But the Irrigated Land Company had no desire to build a canal or tunnel through the mountain side to supply water to the Sanpete Valley.
Instead, the company wanted to build a dam so water could be stored to irrigate 25,000 acres in Carbon County.
The company started to plan for the actual dam and construction began in 1908. But financial difficulties surfaced a second time.
In 1911, the project manager reorganized to form the Price Irrigation Company and construction at the site moved forward.
But even with backing from the state of Utah, progress was slow due to financial problems and the lack of demand for water in Carbon County.
However, as the money came on line, portions of the project were completed.
Finally, the reservoir was allowed to start filling around 1915, although the structure was not completely finished.
The total water volume stored in the reservoir behind the dam never reached the intended size because the project was not completed.
Estimates indicated that the reservoir, when completed, could contain approximately 37,000 acre feet of water. But the reservoir’s peak level before the dam broke registered at 11,000 acre feet.
The collapse of the Mammoth storage reservoir structure was followed by the concept of constructing of a dam in Pleasant Valley to store water in what later became known as the Scofield Reservoir.
The dam at Scofield was constructed in 1926 under the direction of the Price River Water Conservancy District and the U.S. Bureau of Reclamation.
The remnants of the Mammoth Dam can be viewed by people visiting the area, located less thanone-half a mile downstream of the present Lower Gooseberry Reservoir.
The reservoir was created with the construction of a smaller dam in 1939 and then reconstructed in 1990.
At the Mammoth Dam site, one significant landmark is the 30- to 40-foot tall concrete water intake tower. The tower allowed water to be released to locations downstream as needed
The hills surrounding the Mammoth Dam site continue to bear the scars from being torn up to provide fill for the dam and two concrete walls continue to stand alongside Gooseberry Creek.
Although Mammoth Dam was never rebuilt, the ongoing conflict regarding the Gooseberry-Narrows reservoir project has resulted in several lawsuits being filed in the courts.
And during the 1950s when funding for the Central Utah Project was up for debate, the United States Congress also became involved in the matter.