Strawberry Tunnel

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This page was last updated on April 14, 2025.

Overview

The Central Utah Project completed a water-only "Strawberry Tunnel" in 1992. An earlier Strawberry Tunnel was started in 1906 by the Strawberry Valley Water Users Association, and the original tunnel was completed in 1913, with Strawberry Dam and Reservoir being completed in 1915. A total of 50,000 acres in Utah Valley was under irrigation using Strawberry water. More water comes from Deer Creek Dam and Reservoir, completed in 1938.

Timeline

April 26, 1906
Work began on the road to provide access to the temporary construction camps at both ends of the Strawberry Tunnel. (Sun-Advocate, April 26, 1906)

(When bids for the construction of the tunnel itself advertised in late June 1906, the planned completion was in mid-June 1908. At the time that bids were to be opened, on August 30, 1906, no bids had been received to be opened. With no bids received, the Secratary of the Interior announced that the government would proceed with the work, as a project of the United States Reclamation Service, using employees hired directly by the government to do the work, which commenced in late September 1906 at the west end of the planned tunnel, at the top of Diamond Fork.)

1910
By early May 1910, the Strawberry Tunnel had been completed to a point 7,080 feet into the mountain, from the western end at the head of Diamond Fork. Three shifts were being worked. Interior water flow of three-second-feet (about 22 gallons per second) had been encountered and was slowing construction. The tunnel was progressing 14 feet per day, passing through veins of mineral wax, asphaltum, and bitumen, as well as discovering animal bones lodged within the rock. By mid-July 1910, progress had reached 8,200 feet, moving forward by 14 to 17 feet per day. By early October, the length was 9,200 feet of the planned 19,000 feet, and the work to add concrete lining had begun. At year's end, the length was 10,500 feet, and a new flow of water had been encountered, with a flow of 3000 gallons per minute. (Salt Lake Herald, May 7, 1910; Deseret News, May 19, 1910; Salt Lake Herald, July 21, 1910; Deseret News, October 3, 1910; January 3, 1911)

(As with so many drain tunnels in Utah's mining districts, where the tunnels encountered water flows of significant volume, these underground flows being drained by tunnels interupted the flow of nearby springs and wells, that in-turn affected the flow of surface streams, which in-turn affected the water volume used by existing irrigation projects downstream. In the case of the Strawberry Tunnel, it interupted the flow of springs feeding the Diamond Fork of the Spanish Fork River.)

1911
The total excavation by early April 1911 was 11,100 feet, with a water flow of 3,500 gallons per minute. The heavy water flow was slowing the progress of excavation. In early July a camp was established at the east end in the Strawberry Valley, allowing work to begin from the east end. (Salt Lake Tribune, April 10, 1911; Deseret News, July 4, 1911)

1911
"The United States Reclamation Service now has under construction the Strawberry Valley irrigation project. The water supply for this enterprise is to be taken from the Strawberry river. A dam across the Strawberry river, 60 feet high and 400 feet long, will develop a storage reservoir with a maximum capacity of 390,000 acre-feet of water. From the reservoir, water will pass through a tunnel 19,000 feet in length, which is now being bored through the rim of the Great Basin, into Diamond creek and thence into the Spanish Fork river. The tunnel will have a capacity of 500 cubic feet per second, and will be concrete lined throughout. Water will be diverted from the above natural streams into many main and auxiliary canals by means of concrete diversion dams, to lands lying contiguous to the towns of Spanish Fork, Salem, Payson and Santaquin, and on to lands on the east side of West Mountain. Approximately 60,000 acres of land will be irrigated by this great government project, all the said lands lying to the east and south ,of Utah lake. A hydro-electric power plant, with a capacity of 3,000 horse power, is a part of the project and is nearing completion. By it water will be pumped to lands that cannot be reached by gravity canals, and the power will also be employed for draining low grounds." (Utah Bureau of Statistics Report, 1909-1910, published in 1911)

The Syar Tunnel was first proposed in the early 1960s. Work finally started on the 5.7-mile, 8-feet-diameter tunnel in April 1989. It was "holed-through" in April 1990, and was completed in June 1992. When completed it replaced the original 1913 Strawberry water-only tunnel. Both the original Strawberry Tunnel and the much later Syar Tunnel had their east intake portals just below the surface of Strawberry Reservoir so that water was flowing through the tunnels as long as the level of the reservoir was at or near the level of the spillway.

More Information

Strawberry Valley Project -- U. S. Bureau of Reclamation website.

Diamond Fork System -- U. S. Department of the Interior website (includes a map)

Central Utah Project -- Wikipedia article about the Central Utah Project, of which the Strawberry Tunnel and Strawberry Valley Project were the earliest components.

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