A 161-foot landslide along the Lewisville Lake Dam will be repaired, The U.S. Army Corps of Engineers says, and the dam will continue to operate as designed and intended.
The USACE released a statement Tuesday saying though there are known safety issues with the Lewisville Lake Dam it is not a risk of failure.
"Lewisville is a well-designed and constructed dam, and it has been performing as designed. We're taking the necessary actions to make sure it continues in that mode," the USACE said in a prepared statement Tuesday.
Flooding in the spring led to a 161-foot slide on the upstream face of the embankment. The USACE said a $6.4 million contract has been awarded to repair the slide. Work is scheduled to begin Jan. 4 and should be completed by May 2016.
"The reconstructed embankment will be protected by stone riprap on the upstream side and Bermuda grass sod on the downstream side," said Project Manager Mike Kingston. "As part of this effort, removal and replacement of a portion of the asphalt roadway and subgrade layers along the embankment crest will be required."
The news comes days after a report by our media partners at The Dallas Morning News saying a breach of the dam, listed by the Corps as the eighth-most-hazardous in the country before spring flooding took place, could put 431,000 people in harm's way.
"Only 34 miles upstream from Dallas, the Lewisville Dam holds back 2 million acre-feet, or 2.5 billion tons, of water when the lake is full. If the dam failed, the magnitude of all that water unleashed from Lake Lewisville down the Trinity River would dwarf the worst dam disaster in American history," The Dallas Morning News reported.
The Dallas Morning News report said the effect of a breach would extend along tributaries of the Trinity River south of Dallas County into Ellis County.
The Corps of Engineers insist all of their dams have gone through an assessment and that study will provide a solution to the seepage issue at the Lewisville Lake Dam.
"Life safety is our main priority within the Army Corps of Engineers," said Col. Calvin Hudson II, commander, Fort Worth District. "Our Dam Safety Program seeks to ensure that Corps-managed and operated dams present minimized risks to life, property, and the environment. Dams are designed and built to reduce flood risk, but they cannot eliminate all risk."
The six Upper Trinity River Basin Dallas/Fort Worth Metroplex flood risk management reservoirs - Benbrook, Grapevine, Joe Pool, Lavon, Lewisville, and Ray Roberts Lakes--continue to capture flood water and then allow discharge of the water when safe to do so. Recent rain events over and since the Thanksgiving time period have resulted in the six lakes holding water in their flood pools. As of today the percentage of flood pool occupied is 59 percent for Benbrook and Joe Pool Lakes, 60 percent for Grapevine Lake, 80 percent for Lavon Lake, 69 percent for Lewisville Lake and 71 percent for Ray Roberts Lake.
These high pool levels have caused some damages to roads, recreational facilities and associated maintenance to the electrical and plumbing operations. High pool levels may also cause serious environmental impacts at many of the lakes.
The district's other 19 flood risk management reservoirs on the Red River, Brazos River, Colorado River, Trinity River and Guadalupe River Basins continue to operate as designed.
