News Release Archive

Reclamation Releases Shadehill Reservoir Information

Possible Ice Jams May Increase Chance of Flooding

Media Contact: Jeff Nettleton, (605) 394-9757, 03/19/2009 13:40
Arden Freitag, afreitag@usbr.gov

For Release: March 19, 2009

The Bureau of Reclamation reports water is being released from Shadehill Reservoir and will likely continue over the next several days. According to Jeff Nettleton, Chief of Facility Operation and Maintenance and Engineering Services for the Dakotas Area Office, recent warmer temperatures have caused rapid melt of snowpack in some areas, which has resulted in increased inflows and filling of the reservoir.

This situation is occurring earlier in the year than normal and, while temperatures have increased enough to melt snowpack, the river below the reservoir is still mostly frozen over. As a result, increasing releases from the reservoir has potential to break up river ice and pile against constrictions in the river channel such as bridges or other structures resulting in ice jams.

"These ice jams can result in increased flooding of low lying areas if they restrict flows and back water up, or they may suddenly break and release a surge of water," said Nettleton. "We continue to closely monitor inflows and outflows and are coordinating closely with our County emergency management partners to inform the public of these additional hazards."

Nettleton explained that the Shadehill Reservoir rose from elevation 2265.98 feet at 1:00 p.m. yesterday to elevation 2273.18 feet at 12:15 p.m. today, which is a little over seven feet of reservoir rise in less than 24 hours. Once Shadehill Reservoir reaches elevation 2272.0 (the top of active conservation storage) water flows unrestricted through the glory hole spillway into the Grand River below Shadehill Dam.

Shadehill Dam and Reservoir are located about 12 miles south of Lemon, S.D. in the northwestern part of the State, and immediately downstream from the confluence of the North and South Forks of the Grand River. The reservoir stores irrigation water for 6,700 acres. Associated diversion facilities divert directly from the reservoir or from the Grand River downstream from the dam. Additional benefits of Shadehill Dam and Reservoir include flood control, fish and wildlife and recreation.

# # #

The Bureau of Reclamation is a federal agency under the U.S. Department of the Interior and is the nation's largest wholesale water supplier and second largest producer of hydroelectric power. Our facilities also provide substantial flood control, recreation opportunities, and environmental benefits. Visit our website at https://www.usbr.gov and follow us on Twitter @USBR; Facebook @bureau.of.reclamation; LinkedIn @Bureau of Reclamation; Instagram @bureau_of_reclamation; and YouTube @reclamation.

Relevant Link:

Dakotas Area Office