Berthelot Holdings, LLC presented the 158-lot preliminary plat for Shadows at Manchac on April 11, 2012, receiving approval conditioned on limiting fill material to 18 inches “and structures to be built on piers.” Ross Berthelot successfully appealed the conditions on May 9, 2012 and proceeded with business as usual, eventually finishing construction and washing his hands of all future issues. Plans included a retention pond, like most others, which has ceased to function as designed and now Ascension Parish is being called upon to fix it.
An item appears on Monday’s EA Drainage agenda:
Approval to enter into servitude/agreement detail negotiations with the HOA of Shadows of Manchac Subdivision in regards to reworking the retention pond of the subdivision. Approval is for discussion only and final decision to be brought back to the East Ascension Drainage Board for a vote. (Commissioner Aaron Lawler)
Shadows at Manchac is located in Lawler’s District 7.
The cost to fix its retention pond, which has never been maintained apparently, comes to $379,811.16 according to the estimate provided by Hartman Engineering. Obviously, the taxpayers who fund EA Drainage works will have to pick up the tab or the retention pond will go unrepaired.
Would the expenditure benefit drainage outside of the subdivision? If not EA Drainage commissioners have to consider Louisiana’s constitutional prohibition of expending public funds to improve private property. Article VII, Section 12:
A) Prohibited Uses. Except as otherwise provided by this constitution, the funds, credit, property, or things of value of the state or of any political subdivision shall not be loaned, pledged, or donated to or for any person, association, or corporation, public or private. Except as otherwise provided in this Section, neither the state nor a political subdivision shall subscribe to or purchase the stock of a corporation or association or for any private enterprise.
One thing is certain, Ross Berthelot and his company will not pony up a nickel to fix the retention pond they dug less than a decade ago. Standard operation procedure sees the developer create the HoA (which happened on September 10, 2013 in the case of Shadows at Manchac), turning over responsibility to residents once houses are sold (which happened beginning in 2018). None of the affected parties managed to maintain the retention pond, and now the onus falls on EA Drainage (or not).
Hartman Engineering assessed the problem:
The original 2013 Construction Plan Set was compared to a recent topographic elevation survey provided by Ascension Parish, and it appears the retention pond has incurred sedimentation in areas throughout the pond. Sedimentation ranges from a few inches to upwards of 18” in some areas. There are internal cross drains within the retention pond that is completely silted in. The existing Rip Rap Check Dams have incurred severe erosion on the outside of each dam. It is hard to determine (under this existing task order and scope of work) if the existing conditions of the retention pond adequately meet the original Ascension Parish design standards/ordinance without providing a more in-depth design assessment. At this time, this is not part of our original scope of work. However, I will say, this sedimentation has potentially reduced the storage capacity to some degree, but overall appears to be functioning as intended. Also, there are two rock check dams that are severely eroding on the outside edge cutting into the slope of the pond bank.
I made several site visits (April and May) after intense rain events, and did not notice any street flooding or a full retention pond. The siltation will continue to worsen over time without any maintenance. There is an existing 30’ dedicated drainage servitude that runs in the center along the length of the retention pond.
The firm recommended the following corrective measures:
In order to properly maintain the retention pond in its entirety, the costs associated with dredging, cleaning and hauling of material would be the responsibility of the HOA and Ascension Parish, unless Ascension Parish can acquire a temporary servitude for access beyond the dedicated 30’ drainage servitude. Ascension Parish can only legally clean inside of the 30’ Drainage Servitude. And, in my opinion, one should not be done without the other, meaning the whole retention pond (inside and outside of the 30’ Drainage Servitude) should be brought back to original design/plan conditions. Another option would be to dredge additional material beyond the original invert of the retention pond such that the retention pond will hold water (minimum of 3’ depth) such that weed and tree growth can be minimized. (See attached pictures of existing pond as of 7-26-21).
In addition, I recommend removing the upstream rock dam and rebuilding the downstream per plans with a sheet pile wall as the center extending into the existing side slopes of the pond bank to prevent future scouring/erosion around the rock dam. Final elevations to be approved by an Engineer.
If EA Drainage votes to pay for Shadows at Manchac’s retention pond fix, how many other subdivision retention ponds will line up for the same largesse?