Update on Canal Repairs Affecting Growers in Nebraska and Wyoming

Excavation continues above the tunnel collapse. A series of three trench boxes, each 10 feet tall by 20 feet wide by 20 feet long will be dropped down into the space as soil is removed. (Photo courtesy the Goshen Irrigation District)
Figure 1. Excavation continues above the tunnel collapse and on Friday a series of three trench boxes, each 10 feet tall by 20 feet wide by 20 feet long, were droppped down on top of the tunnel to create a safe place for working. (Photo courtesy the Goshen Irrigation District)

Update on Canal Repairs Affecting Growers in Nebraska and Wyoming

The Goshen Irrigation District gave an update on the progress of the tunnel repair Friday during the weekly Fort Laramie-Gering Irrigation Ditch Situational Update conference call.

The district reports that the excavation of the soil continues from the crater above the tunnel at the site of the July 17 collapse. The contractor is installing a set of trench boxes over the tunnel where the collapse occurred.

Each trench box is 10 feet tall, 20 feet wide, and 20 feet long. Three of these are joined end-to-end to form a trench box 60 feet long. The first set was installed earlier this week, the second set was placed over the first set and installed Thursday. The third set of trench boxes is expected to be installed by Sunday, Aug. 25.

As these trench boxes are installed, the soil inside is removed and the trench box drops down closer to the tunnel break. Once all of the trench boxes are in place and the soil is removed, work inside the tunnel can continue with a much smaller danger of further collapse from soil and rocks above.

At this point it is believed the tunnel walls are still intact at the collapse site and have not caved in. Work in the tunnel has progressed to about 700 feet in from the tunnel entrance.

The tunnel collapse and resulting breach of the main canal bank just upstream on July 17 left more than 100,000 acres of irrigated land without water for more than five weeks in Goshen Irrigation District in Wyoming and Gering-Fort Laramie Irrigation District just across the state line in Nebraska. As of Friday, prospects remained uncertain for restoring water this irrigation season.

Tunnel ceiling at midpoint of first breach
Figure 2. Tunnel ceiling at the midpoint of the first breach, 624 feet in from the tunnel entrance, shows where it's been shored up and patched. (Photo courtesy of the Goshen Irrigation District)
Ceiling at the start of the second tunnel breach
Figure 3. Tunnel ceiling at the start of the second breach, 667 feet in from the tunnel entrance. This is the site of the greatest repair need. (Photo courtesy of the Goshen Irrigation District)

Nebraska Extension and the University of Wyoming Extension are working together to share information and help growers in both states understand their options during this severe situation. A joint web page has been created so stakeholders can get information relating to the situation. The URL is https://go.unl.edu/canal. Updates are also available in CropWatch at cropwatch.unl.edu/tags/canal-irrigation.

For more information on the North Platte River and the irrigation projects in Nebraska and Wyoming, visit the slideshare presentation found on the University of Nebraska Panhandle Research and Extension Center web site at https://www.slideshare.net/dostdiek4/north-platte-river-irrigation-system-v21/dostdiek4/north-platte-river-irrigation-system-v21