Water began flowing in the Gering-Fort Laramie and Goshen irrigation canal early Aug. 28 for the first time in about six weeks. Tunnel No. 2 on the main supply canal collapsed on July 17, causing a canal breach and disrupting service to more than 100,000 acres of irrigated crops in Scotts Bluff County, Nebraska, and Goshen County, Wyoming.
Around 6 p.m. Wednesday, Aug. 28, the Goshen Irrigation District (GID) released water from Whalen Diversion Dam on the North Platte River west of Fort Laramie, Wyoming, into the Goshen / Gering-Ft Laramie irrigation canal. The diversion was approximately 600 cubic feet per second (CFS), or 269,280 gallons per minute. The water front reached Tunnel No. 2 entrance around 3:30 a.m. Thursday, Aug. 29. GID and U.S. Bureau of Reclamation personnel were on site to observe any leaks in the newly constructed canal bank and bed.
The volume of water in the canal was to be gradually increased to a flow rate of 800 cfs (359,040 gallons per minute) and monitored over the 24 hours following the first releases. If there were no problems after another 24 hours, the flow rate was to be increased to 1,000 cfs (448,800 gallons per minute). At this time, there is no indication when growers under the irrigation districts can start to take water for their fields. It will take approximately 5 days for the water to travel the 130 miles of main canal.
Prior to the release of water into the canal, trench boxes were put in place above the tunnel to keep additional soil from entering the tunnel through the main collapse site. These boxes are 10 feet high, 20 feet wide and 20 feet long. Three sections are joined together and placed one on top of the other.
The main tunnel collapse site/hole has not repaired. It is shored up to prevent more soil from entering the tunnel. Contractors removed most of the soil from the tunnel, leaving a small amount of soil on the bottom. This soil will be flushed out by the water flowing through the tunnel. The main tunnel collapse site was not repaired at this time as it was more important to get water flowing again in the canal system. Once the 2019 irrigation season has passed, a more permanent fix will be determined. Both irrigation districts are working on long-term solutions and funding for all three tunnel structures on the canal system.
There is still much work to do, and many challenges facing the affected farmers and communities, but the irrigators and everyone else can literally see the light at the end of the tunnel.
Nebraska Extension and the University of Wyoming Extension have been working together to share information and help growers in both states understand their options during this severe situation. See their website at go.unl.edu/canal
Please see https://cropwatch.unl.edu/tags/canal-irrigation for additional stories.
For more information on the North Platte River and the irrigation projects in Nebraska and Wyoming, visit the slideshare presentation on the University of Nebraska Panhandle Research and Extension Center web site.
