Jul 05, 2023

Reclamation announces lowering of Guernsey Reservoir in preparation for annual silt run

Posted Jul 05, 2023 5:04 PM

Press release by: The Wyoming Area Office of the Bureau of Reclamation

MILLS, Wyo.— The Wyoming Area Office of the Bureau of Reclamation in Mills, Wyo., will be lowering the water level in Guernsey Reservoir in preparation for the annual silt run. The silt run is an operation which provides silt-laden water to Goshen, Gering-Fort Laramie, and Pathfinder Irrigation Districts under contract with Reclamation. As the silt-laden water gets diverted into an irrigation canal, the water slows down and the silt sinks to the bottom of the canal. This works as a type of temporary sealant to help minimize the seepage out of the bottom and sides of the canal.

On evening of July 9, the release of water from Glendo Reservoir will be decreased from approximately 3,500 cubic feet per second (cfs) to a flow of between 2,000 cfs and 1,000 cfs. The decreased flow will cause a rapid decline of the Guernsey Reservoir level of approximately 25 feet starting the morning of July 10 and continuing through July 16. By Saturday, July 15, the boat ramps at Guernsey Reservoir will no longer be useable due to the low reservoir level. Water being released from Glendo Reservoir will flow through Guernsey Reservoir, flushing silt from Guernsey Reservoir into the canals of downstream irrigators. The silt run will begin on July 16 and is anticipated to continue through July 29.

Beginning on the evening of July 29, the release of water from Glendo Reservoir will be rapidly increased to refill Guernsey Reservoir. The level of Guernsey Reservoir is expected to be suitable for boating again by the morning of Aug 1. However, the reservoir will continue to rise by approximately 3 feet per day and is expected to reach the normal reservoir operation level on Friday, August 04.

Guernsey Reservoir is the furthest downstream reservoir in the system of Federal storage reservoirs on the main stem of the North Platte River. During the irrigation season, water released from Guernsey Reservoir serves irrigation development in eastern Wyoming and western Nebraska and produces hydropower.

Boaters, recreationists, and irrigators should take proper precautions regarding changing river flows below Glendo and Guernsey Reservoirs and the rapid lowering and refilling of Guernsey Reservoir.