The Dam Called Trouble -- Endangering over 400,000 in Dallas area
The Army Corps of Engineers will need millions of dollars to repair the Lewisville Lake Dam, one of the nations most dangerous. A breach could put 431,000 people in harms way.
The problem one of many first appeared as last Mays record rainstorms quickly filled the regions reservoirs. An instrument at the Lewisville Lake Dam showed pressure building under the downstream side.
Jason Vazquez, dam safety program manager for the Army Corps of Engineers at the time, collared another engineer, and in pelting rain they raced to the affected area, officially known to the Corps as Seepage Area No. 1.
Even during the seven-year drought, the area had looked like a swamp, covered with chest-high cattails and weeds. Corps technicians sometimes encountered water moccasins and alligators as they measured seepage. This time, Vazquez and his partner, wearing rain slickers and rubber boots, spotted something far more disturbing: water and sand bubbling up from a tiny hole in the ground.
Such a sand boil indicates that increasing seepage has created a passage under the base of the dam. If not stopped, it could lead to a rupture of the dam.
Read more:
http://interactives.dallasnews.com/2015/lewisville-dam/
[font color=330099]For those unfamiliar with Texas the Lewisville Lake Dam is 24 miles upstream from Dallas.[/font]