Posted on December 18, 2018
Now that the Comite River Diversion Canal has received the $343 million needed from the federal government to begin construction, all eyes are on a $1.2 billion pot that will pay for the next generation of south Louisiana flood control.
Several projects are in the works, and officials are laying the groundwork to pitch others. The thought of pumping Bayou Manchac is falling out of favor and the Darlington Reservoir is still a dream, but there are plans like knocking out a ridge under La. 22 in Ascension Parish and dredging at least part of the lower Amite River in Livingston Parish — though it remains to be seen whether dredging larger stretches is in the cards.
East Baton Rouge leaders feel a bit hamstrung. Federal agencies recommend communities prepare a storm water master plan, which the parish doesn’t have. Officials decided to commission a report but the parish needs some of the federal money to pay for it. So far, the Federal Emergency Management Agency hasn’t given an answer, city-parish Transportation and Drainage Director Fred Raiford said Friday.
The city-parish has already spent about $2 million but will need about $13 million more, he said. Contractors with the firm HNTB have compiled data and put together a framework for the study, but they’re working only on the Claycut Bayou watershed while they wait on word about future funding that would allow them to study the rest of East Baton Rouge, said program manager Melissa Kennedy.
East Baton Rouge leaders are celebrating a $255 million award to clear, dredge and widen five parish waterways: Bayou Fountain, Jones Creek, Beaver Bayou, Ward Creek and Blackwater Bayou.
Authorities are tugging the reins a bit — in the decades since the proposal was first advanced, there’s been new riparian development. Some stretches of waterways, especially Jones Creek, were to be lined with concrete to slough water downstream faster, but engineers are investigating whether that’s still a good idea, or if it would exacerbate flooding farther down the line.
Raiford said the money must be spent in the next three to five years.
Livingston officials have gotten money to clean up the Amite and Blind rivers by treating them as coastal protection projects that are nonetheless expected to help in times of high water.
Using $8 million from the Deepwater Horizon settlement and offshore oil revenue, the parish will dredge the mouths of both rivers where they enter Lake Maurepas and use the silt to rebuild the banks. Then, vegetation will be planted at both sites to keep them from eroding again, said Livingston Parish emergency preparedness director Mark Harrell.
It will keep water moving more quickly during a flood, he said.
Livingston Parish has also put in a $10 million grant application to repair the rock weir — an underwater dam — that separates the Amite River from the Amite diversion. Harrell is waiting to hear back. The weir has worn down over the years, and now too much water flows down the diversion, leaving the Amite dry.
After the 1983 flood, authorities thought up many storm water-control strategies, including the Comite diversion and building levees along the Amite near Denham Springs. Harrell doesn’t expect the latter, though.
“I don’t see that happening, but again, I’m not an engineer,” he said.
He and others interviewed for this story would be very happy with the construction of the so-called Darlington Reservoir, which could hold water from the Amite near the East Feliciana-St. Helena Parish line. Once thought dead, the proposal enjoyed renewed interest following the 2016 flood.
It’s one of several ideas still on the table, said Congressman Garret Graves, R-Baton Rouge. He’s also interested in improvements to Bayou Manchac. Perhaps reservoirs along that bayou could hold water during a flood, or a pumping station could redirect water into the Mississippi River ahead of and during a storm.
Ascension Parish has considered pumps, but HNTB has determined such a program would provide only limited benefit, according to a presentation given to the parish drainage board.
You just can’t build a pump big enough to counteract a flood, said Ascension Parish infrastructure director William Daniel.
“It will not keep those houses from flooding,” he said.
HNTB recommended two other projects. The first is a $186 million plan to knock down much of the natural ridge under La. 22 so floodwater could drain into the McElroy Swamp. The second is a $61 million plan to dredge Bayou Conway and install a pumping station so it could empty into the Mississippi River.
Further plans are likely to crystallize as the half-dozen ongoing studies conclude. The state Department of Transportation and Development commissioned a study of the basin using aircraft-mounted lasers to accurately measure the region’s topography and make a model. That tool should be ready in January or February, department spokesman Rodney Mallett said.
The U.S. Army Corps has received $3 million to consider flood-control projects around the Amite and its tributaries. Work has just begun, but Corps engineers expect to have a public draft feasibility report finished by December 2019, said spokesman Matt Roe.
Kennedy, the HNTB consultant, said that until more work is completed, it’s too early to tell whether she’ll recommend East Baton Rouge pursue new detention ponds, enlarged pump stations, improved sewerage or some other strategy. The difficulty, she explained, is making sure an improvement to one area doesn’t wind up sinking somebody else up or downstream. Like doctors, engineers must first “do no harm,” Kennedy said.
Graves is excited by the possibilities but urged his constituents to have realistic expectations.
“We shouldn’t rest on our laurels,” the congressman said. At the same time, “we need to get a better understanding of how the water’s going to behave.”
Asked about future funding, Graves said Louisiana needs to figure out how far it can get with the projects that have already been green-lit and the $1.2 billion still in the bank. There’s no need for a new Ferrari when your Ford still works, he mused.
Source: The Advocate
