The gist: Dredging the Vermilion is becoming a political movement in Lafayette, driven by the trauma of repeat flooding events since the catastrophic no-name floods of August 2016. Studies continue as engineers and public officials debate the efficacy of digging out the bayou.
To dredge or not to dredge: Officials, engineers and advocates debate it while Lafayette residents demand it
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“Unclogging the Vermilion River is the first step to solving this problem,” said Paul Baker, headmaster of Episcopal School of Acadiana in remarks to the City-Parish Council Tuesday night. Baker’s home along the St. John coulee flooded in 2016 and again during the June 2019 “rain bomb.” He exhorted the council to take action, worrying that officials may shrug off solutions given the magnitude of the problem. “My wife and I live in fear of the rain,” he said, “and that’s not a healthy way to live in South Louisiana.”
Many now credit Dredge the Vermilion activists Harold Schoeffler and Dave Dixon for driving the conversation. Dixon and Schoefller were behind the push to stop pumps north of Lafayette Parish ahead of Tropical Storm Barry, which in part lowered the base level of the bayou when joined by a favorable and powerful north wind. It’s not clear which intervention — man’s or nature’s — did most of the work lowering the river’s level. Regardless, the episode has given the pair a lot of credibility among residents.
Meanwhile, studies and stakeholder meetings continue. The Army Corps of Engineers is studying the Vermilion River before it will commit to dredging the entire bayou through Vermilion Parish. A hydrology and hydraulic study is expected to be completed by December 2019, according to Greg Ellison, an aide to U.S. Rep. Clay Higgins who presented to the council Tuesday.
There is dispute about what impact dredging would have. Some engineers push back against the narrative that lowering the Vermilion would have the impact clamored for by repeated flood victims. Not all flooding in the parish is related to river back flow. Youngsville City Engineer Pam Granger pointed out at a GOP town hall Tuesday night that flooding in the bedroom community is not connected to the Vermilion. Other neighborhoods in Lafayette itself, like Quail Hollow, reportedly would not benefit from river dredging. LCG Public Works Director Mark Dubroc, exasperated, openly questioned whether digging out decades of muddy bottom would do any good.
“All of this conversation is devoid of technical support,” Dubroc said, drawing derisive cackles from the audience. He noted the Corps of Engineers last dredged the river in the mid-90s to restore navigability, not address stormwater management. However, residents along the bayou, including Councilwoman Nanette Cook, claim that dredging effort stopped water from reaching their homes.
Let’s talk detention. Some use of detention/retention — mechanisms of holding stormwater and slowly releasing it into coulees and the river — is expected to be part of whatever strategy is implemented long term. Dubroc said older developments, built before retention was required by local government, are in part responsible for the extra runoff. He said 4,000 to 7,000 acres of retention could be needed to do any good. That’s roughly the size of a square bound by Johnston and Ambassador Caffery, Kaliste Saloom and Pinhook.
Right now, spot dredging is on the table. Pushback from Vermilion Parish and continued studying will delay full dredging. Vermilion Parish officials, also represented in Congress by Higgins’ office, say the move could worsen flooding in the area and cause saltwater to invade the low-lying parish, imperilling seafood commerce. That leaves dredging “hot spots” to be the remaining option within Lafayette Parish. Again, there’s some question whether that approach would deliver the solution desperately wanted by many who live along the bayou.
Ellison said the council could spot dredge now. He relayed conversations with the corps in which officials offered to help LCG get a permit to spot dredge the river. Council members committed to finding the money in the upcoming budget process. Ellison guesstimated that spot dredging could cost $5 million and that LCG could draw the money down out of $1.2 billion in HUD dollars Congressman Higgins helped secure.
Congress has authorized dredging the Vermilion. We reported that last year. That essentially means the money has been allocated but not delivered.
What to watch for: Whether LCG moves forward with an intermediate dredging plan. It’s election season, and political pressure from flooded-over constituents could prevail on local officials to take the step. To be sure, it’s not a sure thing that even spot dredging would make an impact. That would take study. Many residents are tired of studies.
The Vermilion River was lowered ahead of Barry. It looks like that worked.
The gist: Pumps that feed fresh water into the Vermilion River were stopped days ahead of Tropical Storm Barry’s landfall. Combined with a lucky north wind, ad hoc flood control efforts lowered the Vermilion by more than a foot, potentially avoiding major flood damage along the bayou.
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The river sat 18” lower than normal when the rains started. Consequently, the river’s crest — the flood height, essentially — was close to 2 feet lower than projected ahead of the storm. You can thank the wind and the folks at the Teche-Vermilion Fresh Water District for that, according to regional officials and local advocates. Harold Schoeffler, a Sierra Club advocate who has pushed regional politicos to get the Vermilion River dredged, lobbied the freshwater district to step in and stop the pumps. On July 8, the district followed through, a step it normally takes ahead of major storms, but not with this much forewarning.
“It wasn’t something we haven’t always done in the past,” Teche-Vermilion Executive Director Donald Sagrera tells me. “It’s just that this time we had the warning.”
It’s tough to say how much damage was prevented. Flooding is localized and hydrology can be complicated. Sagrera gives much more credit to the wind than the intervention, but Acadiana Planning Commission Chairman and St. Landry Parish President Bill Fontenot, who had a hand in authorizing the move, says stopping the pumps likely made a big difference for homes along the bayou.
“The stages would have been higher,” Fontenot says of conditions if the freshwater district had not moved. “I think overall the elevations in the system would have been higher. As much as a foot. That could have impacted who knows how many homes and how much property damage.”
What difference does a foot make? If you’re along the river, a lot. It only takes a couple of inches to ruin a home. And to be sure, homes still flooded in areas around Lafayette Parish. Whether dredging the Vermilion, thereby lowering the river long term, is the right solution is a question Fontenot believes ought to be studied. Widening the channel could have unintended consequences that worsen flooding in other areas. “It’s a lot more complicated,” Fontenot tells me.
Flooding here and flooding there. How to manage stormwater will vary by address. While lowering the Vermilion impacts the water level of upland coulees and ditches, it’s not a slam dunk that fixing the Vermilion will save homes that flood from overtopped coulees. There’s even some question whether dredging the Vermilion would prevent flooding whatsoever, given the sheer volume of water entering drainage systems from intensifying rainfall and development runoff.
“There’s no the drainage problem. There are several,” UL geosciences professor Gary Kinsland tells me. Kinsland has studied the Vermilion for years, authoring a paper on the impact of urbanization. Kinsland calls the preventative measures taken by the fresh water district a “no-brainer,” but warns against angling for a singular solution. “There is no silver bullet,” he says.
Why this matters. Stormwater management is everything in Lafayette now, and we’re facing down an election season. While we’ve begun to address the problem regionally, the anxieties created by the floods of 2016 reopen with each looming storm. How to fix the problem will frame much of this year’s political debates, and tackling the Vermilion is a big part of that discussion.
Congress authorizes dredging of Vermilion River Homeowners have demanded work on the river to remove build-up believed to have worsened the historic floods of 2016.
Sen. Bill Cassidy’s office said the Corps of Engineers will release a work plan later this week, which would be the first indication of a timeline for the Vermilion dredging project.
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Lafayette has a river. Why no river walk?
Lafayette doesn’t have a riverwalk like San Antonio or Chattanooga, or lots of other cities for that matter. Why, exactly, is that the case?
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Council readies to dredge the Vermilion, but waits for the Corps of Engineers
The gist: A resolution adopted unanimously by the City-Parish Council Tuesday formally urges action on dredging the Vermilion River. Council members and dredging advocates are now targeting funding and political help while the Army Corps of Engineers completes a dredging study.
There is immense political pressure to act. Facing repeated floods and sustained anxiety since August 2016, many residents say little has been done to protect them. Dredging advocates Harold Schoeffler and Dave Dixon have won the ears of officials, most notably U.S. Rep. Clay Higgins, and have rallied flood victims and politicos alike to take comprehensive steps to manage regional waters. The tip of that spear is dredging the Vermilion River to remove years of accumulated.
“The Vermilion River is in a state of emergency,” Dixon told the council Tuesday night. An August navigation depth survey by the Corps of Engineers shows clogging throughout the river in Lafayette Parish, which Dixon believes is the culprit behind increasingly more common flood events.
LCG needs a permit from the Corps to dredge the river. Before the Corps will OK dredging, it’s studying the impact it would have locally and downriver in Vermilion Parish, where officials have asked for caution.
The Vermilion has reached flood stage five times in the last year. Indeed, over the last three decades, flood events along the Vermilion have increased dramatically, a phenomenon that correlates with population growth and accompanying development.
Climate and development appear to play key roles. Some evidence suggests that rain events are getting more intense. Researchers at LSU found that southern Louisiana is getting more so-called “convection showers” — high intensity downpours that burst over shorter intervals, often overwhelming drainage systems. Meanwhile, Lafayette Parish has added acres of rooftops and pavement that shed more water more quickly into drainage channels and, ultimately, the river.
Public Works Director Mark Dubroc attributes the increase in flood events to those rainfalls. Dubroc has questioned whether dredging will have the impact touted by advocates, arguing earlier this month that there is little evidence to support claims that dredging would have substantial benefit. More to the point, Dubroc is concerned that conclusions are getting ahead of proof. He doesn’t oppose dredging in and of itself, but he questions whether the benefit would be worth the cost.
“As public works director, I need substantive, identifiable benefit,” Dubroc tells me.
UL Lafayette researchers are modeling the effect of dredging the river. Responding to the public momentum, Emad Habib, a professor of civil engineering at UL, has used a detailed river model to calculate the efficacy of dredging.
UL’s model ran a scenario in which 20 miles of the Vermilion was dredged at varying depths and widths, including leveling the shoals at Coulee Mine and Rotary Point, identified by the Corps’ August survey. In a simulation of the August 2016 storms, the most extensive dredging modeled reduced water levels by at most half a foot and only at the Surrey Street bridge and Coulee Ile Des Cannes.
“The benefit is not universal in terms of the location. How much and where you dredge” is what really matters, Habib says. It remains an “open question,” he adds, whether more routine storms would see better results. A 1995 study by the Corps of Engineers suggests that dredging could see greater benefit in smaller storms, estimating a 2-foot reduction in peak water levels after 35 miles of excavation at a cost of around $30 million. Habib’s team will run the smaller storm scenarios through its Vermilion model, which includes more recent data and conditions.
Despite the unknowns, council members are chasing funding. Councilwoman Nanette Cook proposed a $5 million line item for dredging the river in an amendment to LCG’s upcoming budget. It’s not clear how much dredging that dollar amount would accomplish and where the money would come from. Elected officials are targeting state and federal pools, including a $1.2 billion flood control package authorized by Congress last year. Local dollars could be freed up by shifting funds from a handful of road projects and into stormwater diversion, as Mayor-President Joel Robideaux suggested in his introductory budget. An aide with Higgins’ office told the council earlier this month that the Corps estimated the cost of dredging hot spots — i.e. the shoals at Rotary Point and Coulee Mine — to be $5 million. Reached for comment Wednesday, a Corps spokesman could not identify the source of that figure by press time.
People are tired of studies, but studies are underway. LCG needs a permit from the Corps to dredge the river and will not receive one until after the Corps’ impact study is completed later this year. At issue is whether dredging upstream in Lafayette Parish could cause saltwater intrusion or loss of marshland in Vermilion Parish, among other complications.
What to watch for: The outcome of further study. It remains disputed among experts what effect dredging might have and what the cost-benefit would be. Come December, some unknowns will be resolved when the Corps completes its study.