LEWISVILLE, Texas - During an Aug. 20 scoping meeting at the Medical Center of Lewisville's Grand Theater, Black Box Theater Room, approximately 50 citizens attended a presentation and were then allowed to comment and ask questions regarding the Lewisville Dam Safety effort.
"I thought the meeting went extremely well," said Lewisville Dam Safety Project Manager, Lauren Fagerholm. "We were able to provide the public a context for the dam safety rating and this really eased the anxiety level. We also received some very good comments from the public that we will use during the course of the study."
The probability of failure and downstream consequences were among the criteria which led to the "very high risk" rating for the dam. Specific issues which will be further studied include seepage through the foundation and instability of the spillway channel and earthen embankment.
"The dam is not in imminent danger of failing and it is still functioning as it was intended," said Fagerholm. "Our level of concern is heightened because of the downstream consequences in Lewisville and heavily populated Dallas."
The risk associated with the Lewisville Dam was first evaluated in 2005 after the Corps instituted a Screening Portfolio Risk Assessment program to assess the risk of all 694 dams in the Corps' portfolio.
The SPRA report completed in July 2005 was reviewed by Corps senior dam safety officials who concluded that the risks associated with the possible poor performance of the dam were above the Corps' tolerable risk guidelines.
As a result, additional studies of the project were initiated. These studies are currently ongoing, and will evaluate appropriate ways to minimize risk associated with the project.
"In anticipation of possible permanent corrective actions, and in order to fully comply with National Environmental Policy Act requirements, the Corps is preparing a project report and a Draft Environmental Impact Statement to identify the environmental impacts associated with any alternatives to repair and reduce risks at the Lake Lewisville Dam", said Environmental Project Manager, Hollie Hunter.
The general study area will be the Lewisville Lake proper and floodplain from Ray Roberts Dam downstream to Interstate Highway 20 in Dallas County. Construction is anticipated to begin sometime in 2018, with an initial cost estimate ranging from $100 to $200 million.
The primary purposes of the Lewisville Lake project are flood risk management, water supply, recreation and non-Federal hydropower.