The north winds of Hurricane Rita swept over Lake Conroe at about 50 miles per hour, whipping the water into eight-foot waves. San Jacinto River Authority Lake Conroe Division Deputy Manager Randy Acerman says the wind and waves knocked off chunks of rock and gravel that cap the dam.
The Lake Conroe Dam is 2.2 miles long and is operated by five retainer gates. When Hurricane Rita came through the lake was about a foot and a half lower than usual because of evaporation. That left more of the dam exposed to the elements.
That top layer of rock, called riprap, is what protects the dam from erosion. But since much of that was torn off, the clay underneath is left exposed. Lake authorities lowered the water level another foot and a half and plan to lower it another six inches over the weekend. That's to protect the dam from waves. But with the lake so low, Acerman says there could be hazards to boaters this weekend.
The same thing happened at the Lake Livingston Dam. The Trinity River Authority is currently seeking repair bids from contractors and forming plans to prevent similar problems in the future. Both the Trinity and San Jacinto River Authorities are hoping to get FEMA funding for the repairs. The Lake Conroe Dam could cost as much as $5 million. The Lake Livingston Dam may be in the tens of millions.