Parish, state officials to discuss U.S. 190 drainage

Parish and state engineers are meeting next week to come up with a solution to the drainage woes along U.S. Highway 190 in Mandeville.

The drainage complications originate with the weir separating a 2,000-foot retention pond in the private Parc du Lac neighborhood on U.S. 190 from the Golden Glen subdivision just to its south.

Golden Glen, built sometime in the 1980s, is the lowest lying of the surrounding neighborhoods of Greenleaves, Cherry Creek, Lakewood Heights and Parc du Lac, all positioned off U.S. 190. Bayou Chinchuba lies at the heart of Golden Glen where the surrounding waters drain and eventually empty into Lake Pontchartrain.

Before making their way to the bayou, when it rains, water drains into the sprawling retention pond in Parc du Lac, finds its way to the 30-foot wide cement weir where it’s supposed to flow gently through the V-notched channel atop the structure and into the maze of ditches in Golden Glen that lead to the bayou.

That channel collapsed several years ago leaving a gaping hole nearly six-feet deep that area children used to play in before crews filled it with riprap. Water continued flowing into the hole hollowing out a large chamber under the weir that a city-hired diver said he was able to stand upright in.

The weir is the responsibility of Parc du Lac’s homeowners but the damage to the dam exceeds the capabilities of the neighborhood’s homeowner’s association, which is why officials are trying to have that land donated to the parish.

The parish was forced to take matters into their own hands after a day of torrential rains eroded large sections of the weir. Fearing its collapse was looming, crews made emergency repairs using riprap. Even with the makeshift repairs, the weir is still deemed dangerous and has been roped off from public access.

The weir will be one of the issues discussed when parish and state officials meet to come up with a solution for draining water through the weir without putting any extra stress on the derelict structure.

The U.S. 190 widening project in Mandeville that turned the ancient two-lane highway into a five-lane freeway is finally wrapping up, but before Parish President Kevin Davis signs on the dotted line, he wants answers to the latest drainage woes that recently surfaced.

Davis’ office has been working with the state’s Department of Transportation and Developoment for some time now, Parish Spokesperson Suzanne Parsons Stymiest said, about drainage around the Parc du Lac and Greanleaves subdivisions.

The recent road construction may have escalated the situation.

“I wouldn’t say it compounded the problems. It certainly didn’t fix it,” Stymiest said.

Water from the Greenleaves neighborhood and the recently completed $30-million Chenier Village is directed under the road and through a set of pipes that lead to the retention pond in Parc du Lac. That’s where the latest problem lies.

The culverts under the road are several feet lower than the pipes draining into the retention pond, backing water up in that area until it reaches the level high enough to flow through the pipes. That’s not good news for residents or commuters.

“At some point, the flow of that water is going to form a sheeting action on top of the road and back water up into other subdivisions,” Stymiest said.

Additionally, “the size of the flow of water that goes under the road is smaller than the parish design team would have liked it to be,” she said.

There’s another worry.

Mandeville officials installed pylons in front of the drainage pipes leading to the retention pond to help support the structure during the road construction. With the runoff water slamming against the wall then pooling there till it can pass through the pipes, they’re worried that support wall will fail when they remove the pylons.

“There are a number of engineering solutions to the problem,” Stymiest said, “which is why the engineers are meeting to discuss it next week. We are very optimistic we will be able to work with the state to improve the drainage.”

At their meeting next week, officials will take into account problems with the weir and drainage on U.S. 190.