“When you build a dam over the top of the aquifer, obviously the water can seep under the dam. Most of the time, since the dam is not holding water, the ground water just flows normally, without a problem,” said Kurt Rinehart, MCD chief engineer.
Problems can occur when water builds up behind the dam, Rinehart said.
“The weight of that water exerts pressure on the aquifer and it pressurizes the water flowing underneath the dam. Under the weight of the dam it’s not a problem, but when you get down stream of the dam, there’s a potential for that water to flow to the surface in an uncontrolled manner, which causes a potential stability problem of the dam,” Rinehart said.
The project, on which construction began last fall, includes installing 3,700 feet of piping to improve drainage from 68 existing relief wells, which relieve pressure from the dam. A toe berm, measuring 2,250 feet long, 300 feet wide and 14 feet tall, and requiring more than 125,000 cubic yards of dirt will be added to counteract the downstream toe of the dam, according to the conservancy district.
Rinehart said the project will have no effect on Englewood’s drinking water supply and the effect on wildlife and the land surrounding the project will be kept to a minimum.
“During construction, we are disturbing a lot of earth. We have storm water controls in place to make sure the sediments don’t get to the river. Part of the project is controlling the sediments off the site so that we don’t have any negative impact on the water,” Rinehart said.
The Englewood Dam is the largest of the dams regulated by MCD and regulates the flow of the Stillwater River into the Great Miami River.
“This just makes sure that the dam is safe. It’s a proactive step to make sure the dam can handle a high level of water,” said Jana Heeg, MCD project manager.
The project is headed by Bruns Enterprises in St. Helen, Ohio, which was awarded the contract in September
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