Work continues on irrigation tunnels

Jess Oaks
Posted 5/22/24

GOSHEN COUNTY – During the early morning hours of July 17, 2019, the banks of the Gering-Ft. Laramie-Goshen canal collapsed, causing a breach in the main canal which furnished water from the …

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Work continues on irrigation tunnels


GOSHEN COUNTY – During the early morning hours of July 17, 2019, the banks of the Gering-Ft. Laramie-Goshen canal collapsed, causing a breach in the main canal which furnished water from the North Platte River to well over 100,000 acres of irrigated crop ground in the North Platte River Valley of Nebraska and Wyoming. It was a day many people will never forget. Homes and businesses were flooded. Area producers lost entire fields from either too much water or not enough. It would take members of the Goshen Irrigation District (GID) and an entire crew to build a temporary solution to save the crops of area producers. Crews worked day and night for over 40 days to provide irrigation water to crops during their essential growing period.

After the temporary solution was put into place, the real problem of developing a solution to repair the over 100-year-old water tunnels began which would require strategic planning. 

“I think it was at 12:15 a.m. on July 17, 2019, we got a high-water alarm. Just upstream from the tunnel, we have a gauging station in various places along the canal and one of them is just above tunnel two. We got a high [water] alarm notice at that local so our current manager, Ron Posten, went up to investigate that,” Kevin Strecker, GID manager said. “About a half hour, 45 minutes, later we got a low [water] alarm at that station, which happened before we were able to get up there because it is about a half hour drive from here to get there. We knew at that point; that the canal had possibly breached. It was the only explanation.” 

When members of GID arrived at the water gauging station near tunnel two, they confirmed the canal had breached.  

“At first, we thought something had got into the canal and plugged the canal, but it actually washed the road out and we had to go back around to the outlet side of the tunnel, Strecker explained. “By that time, it was getting close to daylight, and we found a big sinkhole above tunnel two, then we knew that the actual tunnel had collapsed.” 

The tunnels were hand-dug over 100 years ago.

“Through years of rainwater trailing through the soils, and going through the cracks of the tunnel, brought sand with it and created a void above the tunnel. For whatever reason, it finally got to a point where a bigger rock fell and hit the ceiling,” Strecker explained. “Those tunnels do not have steel reinforcement. It is just concrete, so it actually broke the roof of the tunnel ceiling which allowed sand to come into the tunnel. The water just couldn’t keep up with the amount of sand that was coming in and eventually just dammed the tunnel. The water had to go somewhere which was, breeching the canal.”

“Tentatively, right now, we are looking at starting on them this fall,” Shawn Booth, GID district one president, Shawn Booth said. “It’s just portal work the way it sounds on both tunnels. This is a schedule that Atkinson (project construction manager at risk) proposed. Of course, we have to get to a 60% design or better to get a GMP, or a gross maximum price, which is what Kevin and I and the districts need to be able to go look for more funding we are going to need.” 

The project, which will take years to complete, has been estimated at an astounding $52-$84 million. 

“So far, what we have for funding is estimated to not be near enough,” Booth said. “Once we get that 60% design, which is around July or August, that is when as far as on the money end of it, we can go to the state legislators, the governor, and of course our US Senators and congress and when I am speaking on those terms, Nebraska and Wyoming of course.”

“This is a pretty unique district or situation because it is two districts in two states, you know, fighting for one cause and trying to get these tunnels rebuilt,” Booth said. “That is kind of where we are in planning. It’s all about the design that is where we are going to get our GMP, and they are still working on that. It’s fairly technical. It involves a lot of hydrology, as you can imagine, to get an increased flow of what we had in the past or last year for sure to where we want to be,” Booth continued.

According to Booth, the districts opted to use a construction manager at risk, instead of a design-built bid, to get better ideas on funding ahead of time. 

“It’s going to be a huge challenge. Our legislators, state and nationally, all are very aware how critical and important this canal and irrigation system is to the entire community and the huge effect that this water has on this community,” Booth said.

Because the project is so large and the window for construction is contingent on the irrigation season and the winter weather in the later months of the year, Booth explained, the project needed to be broken down into stages. 

“Of course, in year two, which would be next fall and winter, we would be in the tunnels,” Booth said. “The design has a lot to do with what it is going to cost. If they can lower the floor a little bit and widen it out a little bit and keep the roof in place above it and shotcrete up against it would be much less expensive than if they had to remove the entire tunnel, including the top of it. That is when the risk really increases, exponentially,” Booth added.

“Right now, they are working on a few different design ideas to carry forward. We know we are going to put new tunnels in the same alignment as the old tunnels, so we know that’s going to be the case,” Strecker said. “It is just a matter of hydronics as to whether how big the tunnel will be and how much needs to be excavated out of and what we have to do there.”

Strecker added Atkinson conducted investigations of the tunnels before the irrigation water was added to the canal. The investigation helps determine what is going on outside of the tunnels and soil types.

“After the emergency repairs, we did some void grouting to eliminate any voids behind the tunnels,” Strecker said. “They want to make sure there are no other voids that will cause problems in the construction of the new tunnels. We are looking at various options of how they are going to dig those tunnels out.”

According to Strecker, all of the work which needs to be done adds to the cost of the project. 

“Like Shawn said, it’s difficult with two districts, but we are working on securing funding together on the discussions of the design and how we move forward,” Strecker said. “We also have to work with the bureau of reclamation because it is a bureau-owned facility, so everything has to be cleared by them and of course, there is a lot of permitting and a lot of NEPA (National Environmental Policy Act) studies,” Strecker explained.

The irrigation canal runs through parts of Goshen County history, Strecker also explained, which has added yet another issue to plan reconstruction around.

“We have a lot of cultural elements up there. We are close to Fort Laramie. Fish and wildlife have to be involved,” Strecker explained. “So, there are just a lot of things that play into this that is critical to our timeline. We are working to bring all of that together. Like Shawn said, hopefully, be doing some construction by next fall. It will probably be at least a two-year project since we have such a narrow window in between irrigation seasons. That is another thing, in order to keep costs down, it will probably be a two-year project.”

Both Strecker and Booth said work would begin on the outside of the tunnels this summer. 

“They may even do some work this summer outside of the tunnels, getting this prepped and ready for this fall,” Strecker said. “They are getting things ready for construction this fall that they can do while water is in the ditch. Building roads if they need to or anything like that. We have had a lot of activity up there and a lot going to happen between now and next fall.” 

When the tunnel collapsed, Strecker said, an emergency repair to get water flowing was done in the summer of 2019, and during the following off-season, void grouting throughout both tunnels was completed.

“That was a big project, just to secure the outside perimeter of those tunnels and make sure there weren’t any voids to make the tunnels safer,” Strecker said. “They also installed steel sets inside the tunnels where the engineers felt that the tunnel may be compromised. I believe there are 56 steel sets in tunnel one and I think there are over 90 in tunnel two. That is what is restricting our flow right now. We are not at maximum capacity in those tunnels. Even though like this year, we are going to have a good water year, but we are still limited on how much water we can deliver to the farmers. That is why it is critical to get this thing fixed,” Strecker added. 

There isn’t much the district can do to increase the current water flow without a lot of costs, according to Strecker. 

“We hate to keep dumping money into tunnels we are going to replace,” Strecker said.

“We did put steel sheeting up and that increased the flow a lot,” Booth added. “The ribs of the tunnels were creating so much turbulence it was similar to a washtub and once we sheeted it and beveled it, front and back, back to the concrete, it seems like we jumped up 100-145 CFS (cubic foot per second) which really helped. It was a short-term investment, but we got an immediate reward for doing it,” Booth said. 

The search for solutions and funding continues for both districts. 

“One the good news is we did receive a grant through the water development from the legislature. It had to go through the budget session again this year and so we did get a $21.8 million grant so that’s huge for us,” Booth said. “You can’t really count on that until it’s gone through legislation. But it went through with a water bill that included funding for some dams and other projects. Between the two districts, we have accumulated close to around $45 million. Projections are anywhere from $75 [million] to $90 [million]. We don’t know. We are guessing $80 [million] so that would mean we have approximately half of what we need. On the money end of it, we got good news, but we still have work to do in front of us.”