Plans laid out for dam maintenence

Reclamation, with assistance from the Garrison Diversion Conservancy District, will be doing maintenance on the Jamestown Dam outlet work over the next several weeks. Minor concrete repairs will be made within the outlet works and an underground drain will be replaced along the east side of the outlet works. Work is scheduled to begin on June 11, and is expected to take three weeks.

“Public access to the downstream side of Jamestown Dam will be restricted for the duration of the repair work,” said Darrin Goetzfried, acting deputy chief of facility operation and maintenance and engineering services at Reclamation’s Dakotas Area Office. “The public should expect lower water levels in the James River downstream of the dam for the duration of the work.”

The concrete repairs are required to repair freeze-thaw damage at the normal winter ice level within the outlet works stilling basin. Replacement of the underground drain pipe to the east of the outlet works is required to better control ground water levels and seepage along the stilling basin, Reclamation said.

Releases from Jamestown Dam will be shut off and an earthen dike will be installed across the James River channel immediately downstream of the outlet works to enable the outlet works stilling basin to be pumped out for the maintenance work. Gates within the Ice House Dam have been opened to lower the James River water level and facilitate the work.

Once repairs are completed, releases will be made in an attempt to maintain the Jamestown water level at the summer target elevation of 1,431 feet. Jamestown Reservoir is currently at elevation 1,430.5 feet.

In addition, the Omaha District, U.S. Army Corps of Engineers, announced Friday that Pipestem Reservoir has reached its summer release of 75 cubic feet per second. Pipestem Reservoir is seven feet above the top of conservation pool and this stored water will be released over June, July and August, as specified in the water control plan for the reservoir.

Pipestem Reservoir is currently at 1,449.5 feet with 5.6 percent of the flood control pool occupied. The reservoir is dropping at a rate of less than 0.1 foot per day. The 75 cfs release was initiated on June 1. Assuming normal rainfall, the current release will be held until approximately Sept. 1, when the pool level is near the normal winter elevation of 1,442.5 feet. Small changes in the release may be necessary depending on the amount of summer rainfall.

River stages on the James River in North Dakota and South Dakota are available on the U.S. Geological Survey website at http://nd.water.usgs.

gov/floodinfo/james.html.

Tags: local news, news, dams, floods