Wednesday, February 17, 2021

Bacon Siphon And Tunnel

Written by me, Dan Bolyard.
Part of the scheme to get irrigation water from the Columbia River was to pump it into the upper Grand Coulee by the pump-generators at the dam site. Water would flow into the equalizing reservoir, now named Banks Lake. From there the water would flow two miles through a canal blasted out of basalt. The next section is the focus of this essay: the Bacon Siphon and Bacon Tunnel, built in 1947.

The name Bacon comes from an old station midway on the Northern Pacific Adrian Cutoff, which ran south of Coulee City to the Great Northern siding at Adrian, a distance of about 25 miles. The odd name's origin is unknown, though one local legend has it there was a run on food at the local general store after the area was opened for homesteading. At one point the only remaining foodstuff left in the place was Bacon. I like the idea that it was named for someone, though I have yet to find conclusive proof either way. .

The siphon and tunnel are actually closer to Coulee City, so the reason for the choice of the Bacon name for the project is unknown to me, though it is distinctive, and unlikely to be confused with any other named location in the project of canals and siphons downstream.

The siphon was the tool used to cross part of the upper reaches of the lower Grand Coulee, namely Don Paul Draw. The project name for the draw is Bacon Coulee. Odd to me is that pioneer settler Dan Paul lived at the very tip, closest to town, so the choice of Don or Bacon just confuses it.

The siphon was to take water from the two-mile main canal, via a 22-foot diameter concrete pipe, with the higher end receiving water at a higher elevation, and then dumping the water into the tunnel at a slightly lower level. There was a modest amount of excavation in the draw/coulee to allow for a smooth flow of the pipe. Once that was done, a metal frame was built in sections, then a form was built before concrete was poured. When finished the siphon was 1,038 feet long.

The Bacon tunnel is of greater interest to me. The area is made up of various lava flows, so the tunnel would have to be blasted through basalt, a lava rock. The rock cools into a large crystalline shape and is difficult to drill through. The tunnel was planned at 10,045 feet long. The contractor, C.E. Connolly, established a siding near the south portal of the tunnel, along the NP branch, aptly named Connolly.

The Connolly camp featured the usual buildings, tents for the men, an air compressor enclosure, an office, a tool sharpening shed, and dynamite storage. In order to remove the spoil from the tunnel, a short section of railroad track was built.

The tunnel was built in the usual style of drilling, blasting, and muck removing. When enough of the 22-foot diameter tunnel was completed to full size, it was lined with concrete. Photos show two sets of tracks exiting the south portal at one time, with later photos showing only one. Small gas-electric locomotives worked the line. the spoil being dumped along a short distance from the portal.

In the photo, we are looking out the north portal on August 5, 1947. The track for the mucking crew is very evident, with a scoop on a railroad car seen on the left. Across Don Paul Draw/Bacon Coulee, a blasted rock is being removed from where the beginning of the siphon will be.

The completed siphon and tunnel were rated for carrying 7.250 cubic feet of water per second. Water demand was so great a second siphon and second tunnel were completed in 1976.

The photographer is unknown, likely a staff photographer from the Bureau of Reclamation. The photo is part of the collection of the Coulee Pioneer Museum in Electric City.

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