Most probable range for combined releases is 1,600 to 1,800 cfs in Jamestown

JAMESTOWN — The most probable range for combined releases from Jamestown and Pipestem reservoirs is 1,600 to 1,800 cubic feet per second after the area received above-normal rainfall during the last two weeks, according to Alex Flanigan, water manager of Pipestem Dam for the U.S. Army Corps of Engineers.

Currently, combined releases are 1,600 cfs from the two reservoirs — 1,100 cfs at Jamestown and 500 cfs at Pipestem.

The reservoir pools will rise slowly for the next two weeks as water from the recent precipitation is stored in the reservoirs, Flanigan said in an email to The Jamestown Sun.

“At this time releases are being held at 1,600 cfs so river levels through town should be stable, barring any new rainfall on the drainage area between the dams and the City of Jamestown,” he said.

Flanigan said the Corps of Engineers will continue to monitor basin conditions and make adjustments to best utilize Jamestown and Pipestem reservoirs within their approved water control manuals.

When the combined releases from the two reservoirs are around 1,700 to 1,800 cfs, the city of Jamestown starts monitoring a few locations where dikes might be needed, said Tyler Michel, public works director.

“There were three areas that we used to have to sandbag,” he said. “Two of them, the landowners got together and did some precautionary measures on their own, but there is one area down by Taco Bell, the townhomes down there, we start watching that area pretty close to see if we have to sandbag.”

Michel said landowners along 17th Avenue Southwest and an area north of Dairy Queen had a dike installed near their areas. The landowners along 17th Street Southwest got the proper permits through the Corps of Engineers and the city of Jamestown to add more protective measures around their lots, he said.

When combined releases are 1,000 cfs, the city plugs catch basins in some areas because the water fills a pipe and then backs up into the stress, Michel said.

“We plug them and then put pumps there to pump the water from you know say we get a rain event, it will pump water directly into the river,” he said. “We rent pumps, we plug the pipe and then we run electricity and everything to the sites to pump water out.”

Michel said the city starts taking other precautionary measures, such as installing clay dikes, HESCO barriers or sandbags among others, for public and private property if releases from Jamestown Reservoir get to 1,800 cfs.

If combined releases reach around the 2,400 cfs range, the city could potentially look at bringing materials in to make sandbags in one of the parking lots in Jamestown.

“We can’t say for sure it would be that but that’s when we are going to start ramping up and taking precautions and probably start getting everything going at that point,” Michel said.

Michel said the city could be looking at some extended releases from Jamestown and Pipestem reservoirs throughout May, June and July. He said water north of Jamestown in areas such as New Rockford and Grace City takes time to get to the Jamestown area.

The higher combined releases affect the city’s sanitary sewer system as well, he said.

“Water gets into the sanitary sewer pipes and then it essentially dilutes the sewer that goes out to the lagoons,” he said. “So instead of treating just sewer, we are treating sewer and groundwater, which is why we have done some of those projects over the years to try to reduce that, but there’s a lot of old areas in town where the groundwater is high when the river is high and we end up sending stormwater out to the lagoons.”

He said the city also sees an increase in run times on its pump stations.

Michel said the effect of the combined releases through Jamestown changes year to year because of projects to remove downed trees from the rivers in the city.

“That clears the river bank up so water flows through better,” he said. “ … One year it may flow really well through there because of all the trees being gone, but then if we get a bunch of trees that fall in or rivers move over time, it takes hundreds of years generally, but it really changes … year to year.”

Michel said the city received grant funding a couple of years ago to armor the banks in a few areas in Jamestown to try to protect its infrastructure such as water lines and water pump stations.

He said if residents see something out of the ordinary related to potential flooding, they can call City Hall at 252-5900.

“We can check it out and see if it is something that needs to be dealt with right away or if it’s something that can maybe wait until the river goes back down,” he said.

Michel also said it helps the entire city if landowners can prevent a tree from falling into the river by trimming or removing some of it. He said the city would try to help if the tree is in a location where its workers can safely trim or remove some of it.

“Anything to help the water get through Jamestown without an obstruction or blocking anything is only going to help the whole city, not just certain neighborhoods, but it really helps the whole city because of the lift station pump times and all of that stuff,” he said.