The state of Louisiana calls them "high impact" or "high hazard" dams. In fact, the seven parishes of Northwest Louisiana are home to 18 of them. But it appears the word hazard may be giving the impression that many of them could fail. And that's not the case. But, we did find one in trouble.
Where the placid waters of Lake Bistineau meet the dam, it serves as the line separating Bossier and Bienville Parishes. But, there is a problem developing at the dam called 'head cutting.' "A long term problem with the outflow cutting a deeper trench running up closer to the dam," explained John Sanders. He is the District Four Administrator for the Louisiana Department of Transportation, headquartered in Bossier City.
Low water levels on the south side of the dam reveal the rocky bottom of Loggy Bayou. Such dry conditions are ideal for 'head cutting' if we were to get lots of rainfall, eventually carving the bottom of the bayou next to the dam.
"The water pressure is so high over here that it's going to push up through the weakened layer," said Don Maddox, while writing a diagram on a large dry eraser board inside their headquarters. Maddox is the Assistant District Four Administrator of Engineering at LDOTD.
He warned that if this long-term erosion is left unchecked within two years dam failure could become a big concern. A long-term plan would include a new dam farther south.
As for the short-term plan, Maddox continued his drawing, this time making big circles a thousand feet south of the Lake Bistineau Dam and saying, "so, what you do is, you go ahead and put heavy stone right here."
Work on the $900-thousand temporary fix for the dam is expected to get underway in the summer of next year. The long term plan, $2 million worth, is expected to get underway in five years. Louisiana state lawmakers already approved funding for the first project. And, funding for the long term project is on the fast track according to Maddox and Sanders.
As for the other 17 'high impact' dams in Northwest Louisiana, KSLA News 12 is told they're all in good shape. Maddox concluded, "it is not that these dams are in danger of failing, it's just that there's some maintenance issues with them." And when it comes to dams, an ounce of prevention really is a pound of cure.
In the past 30-years, the government reports 135 deaths and more than $2.6 billion in property damage from dam failures nationally. None happened in Louisiana.