(Dallas News) The problem — one of many — first appeared as last May’s record rainstorms quickly filled the region’s 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.

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