Plan developed to permanently repair irrigation tunnel
November 28, 2019
TORRINGTON – The Goshen Irrigation District and the Gering-Fort Laramie Irrigation District have decided on the best method for permanently fixing a tunnel that collapsed along the Fort Laramie Canal in July.
According to a press release issued by the GID, the permanent fix for the tunnel will build on the work completed this summer by SAK Construction, which was done as a temporary solution to repair tunnel No. 2 along the canal. SAK workers installed heavy-duty steel ribbing inside the 100-year-old structure and reinforced the walls and ceiling with grout.
The permanent fix, according to the release, will be to install more ribbing and support, and use a chemical grout to reinforce the outside of the tunnel.
“The plan includes interim repair work to stabilize the tunnel with additional ribbing supports and void grouting for the 2020 water season, as well as initiating a chemical grouting process to the tunnel that will stabilize and harden the outside of the tunnel permanently,” the release said. “The boards considered over 10 options after consulting with the United States Bureau of Reclamation analysis of the many options for permanent repairs. Both districts continued to gather additional cost estimates, further research the grouting technology, and consider the prior work completed during the temporary fix to the tunnel.”
With all of the options on the table, GID manager Rob Preston commended both boards on coming to a decision.
“Both boards went beyond their duties to study, analyze and decide on a sound and solid decision,” he said. “I commend both district boards for the leadership they demonstrated to make a tough decision that ultimately affects this entire valley and its agricultural economy.”
The chemical grout, the release said, will be strong enough to stabilize the tunnel well into the future. The GID has not announced a projected cost for the repairs, as the district is in the process of collecting bids for the project.
“Interim tunnel work has commenced and will continue in the upcoming weeks,” the release said. “The initiation of the planning, engineering and environmental permitting for the permanent fix will begin shortly after the decision.”
Tunnel No. 1 along the canal will be grouted as well, the release said, in a proactive move after officials found some cause for concern in the tunnel.
“The same grouting process will also be used to stabilize, repair and secure tunnel No. 1, which after the collapse, was identified for additional repairs and long-term stabilization for the tunnel’s structural integrity.”
Over the past week, the canal was thoroughly inspected by GID, GFLID and USBR personnel to identify potential problem areas, the release said.
“After the inspection, the USBR identifies and compiles a report identifying critical areas of repairs and maintenance to be completed by the districts before the 2020 irrigation season, in addition to its tunnel repair efforts,” the release said.