Park City celebrates rehabilitation of mining-era tunnel, a crucial water supply |

Park City celebrates rehabilitation of mining-era tunnel, a crucial water supply

There was a high risk of a collapse, something that would have been devastating

Park City leaders are preparing to celebrate a project at the Spiro Tunnel on the edge of Thaynes Canyon that is designed to protect an important municipal water source and highlight the history of the location.​
Courtesy of Park City Municipal Corp.

The Spiro Tunnel, tucked away on the edge of Thaynes Canyon, has never seemed to attract the same attention as other silver mining-era relics in the Park City area.

It does not soar into the air like the derrick-like Daly West Mine head frame in the upper reaches of Deer Valley once did and soon will again. Nor does it occupy one of the postcard views of Park City, like the towers of the Silver King Aerial Tramway along the route of the Town Lift.

But the Spiro Tunnel played an important role in Park City’s mining era and continues to be a crucial location in modern Park City as a key source of drinking water. The history of the Spiro Tunnel and the role in the waterworks system will be celebrated on Tuesday as City Hall completes a major project designed to protect the water source and tell the background of the site. Park City officials and a group called the Friends of Ski Mountain Mining History are teaming to organize the event.

The waterworks aspect of the project is especially noteworthy as officials continue to attempt to protect the drinking-water system. Some of Park City’s drinking water comes from underground sources, such as the Spiro Tunnel. Officials for decades have worked to protect the underground water sources from the danger of cave-ins or other problems.

In the case of the Spiro Tunnel project that will be highlighted next week, crews hired by City Hall worked on the first 400 feet of the tunnel in a rehabilitation and stabilization project. Rocks were starting to cave in, influencing the municipal government to proceed with the project. There was a “high risk” of collapse inside the tunnel, said Clint McAffee, the public utilities director for City Hall. A release from City Hall outlining the upcoming event indicated the walls had deteriorated over the course of 100 years. McAffee said it would have been “catastrophic” if the tunnel collapsed.

The Spiro Tunnel provides between 25% and 30% of the total water produced by the municipal system. A portion is drinking water used across Park City while some of the other water is used for snowmaking purposes on the Park City side of Park City Mountain Resort as well as for irrigation at the Park City Golf Club and the Park Meadows Country Club golf course. The Spiro Tunnel water also flows through McLeod Creek.

“This is a significant portion of the total water supply,” McAffee said.

A revamping of the the Spiro Tunnel entrance, shown on Wednesday, is a part of a broader project at the location. Panels explaining the history of the Spiro Tunnel are expected to be installed as a celebration of the project approaches.
Jay Hamburger/Park Record

City Hall tapped a mining engineer and contractor for the work. A stretch of tunnel measuring nearly 2.5 miles in length was assessed. The 400 feet closest to the mouth of the tunnel were the “worst condition and highest risk,” he said. The contractor replaced the steel and wood that held up the tunnel with concrete applied through a method called shotcrete. Concrete rock bolts were also used to secure the walls. McAffee said officials hope the work lasts for decades. The project also included replacing pipe that was failing and the replacement of pipe that collects water at the 400-foot mark for the diversion to the 3Kings water-treatment plant currently under construction off Three Kings Drive. The project cost approximately $4 million and was funded through water-service fees.

The municipal government will eventually install mechanical equipment that will circulate fresh air into the tunnel to ensure safe oxygen levels for workers.

“It just brings me comfort because it continues to protect water and secures this water source for the community,” McAffee said.

Park City’s influential historic-preservation community will also hail the project. The work included the construction of a plaza dedicated to the community’s silver-mining heritage. Park City was founded in the 19th century as a silver-mining camp, and the industry drove the economy for decades before collapsing amid a steep drop in silver prices. The ski industry eventually rose to reignite Park City.

Park City leaders, preservationists and tourism officials have long seen the mining history as something that sets the community apart from some of the modern mountain resort rivals in the U.S. The mining heritage is widely celebrated with the preservation of relics in places like Old Town and across the mountain resorts. The celebration at the Spiro Tunnel is planned in the weeks before the head frame of the Daly West Mine is scheduled to be put upright again in Empire Pass, more than six years after the hulking structure collapsed. Returning the head frame to an upright position will be seen as another milestone in the community’s preservation efforts.

The event on Tuesday is scheduled from 5 p.m. until 6 p.m. at the Spiro Tunnel opening, located at the plaza at Silver Star. Park City leaders and the Friends of Ski Mountain Mining History are expected to be in attendance. The event will offer a rare opportunity to enter the tunnel. Tours require closed-toe shoes. Park City officials strongly encourage masks at the event. There is limited parking and City Hall encourages event-goers to walk, bicycle or take a bus.

More information about the event is available on the City Hall website, The direct link is:

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