Work necessary to prevent more erosion; weather caused delay
Work is under way to repair the 160-foot-long landslide that stretches along a section of the 6.2-mile Lewisville Lake Dam, the U.S. Army Corps of Engineers said.
Weather delayed the corps from beginning repair work last month as planned.
But the corps over the weekend said the contractor overseeing the $6.4 million repair is now on site and expected to complete the project by late spring or early summer.
“The reconstructed embankment will be protected by stone riprap on the upstream side and Bermuda grass sod on the downstream side,” Mike Kingston, the corps’ project manager, said in a statement.
“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 corps, which manages Lewisville Lake for the federal government, had covered the landslide with tarps to protect it from rain, using rocks, sand bags and wooden pallets to hold the tarps in place.
Severe thunderstorms late last year wreaked havoc on the tarps, exposing the vulnerable landslide to more than 16 inches of rain that bombarded the North Texas area over the Thanksgiving and Christmas holidays.
The landslide repair is necessary to prevent further erosion at what the corps rates as the eighth-most-hazardous dam in the country. Failure of the dam could send a wall of water 65 feet tall sweeping toward downtown Dallas. More than 400,000 people live in the water’s path.
The 161-foot-long, 23-foot-wide landslide appeared in late June after record rainfall and is adjacent to another major slide that occurred in 1995.
After The Dallas Morning News and the Denton Record-Chronicle published a report about the threat to Lewisville Lake Dam, three members of the North Texas congressional delegation pledged to raise money to accelerate repairs.
The corps estimates that permanent repairs will cost between $50 million and $500 million and would take several years.
The corps has taken steps to lower the lake level to repair the landslide by releasing water downstream and said in statement that despite “some known dam safety issues, it is not at risk of failure.”