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Two years and waiting: a look inside the drainage action plan

Pam Suire looks over the coulee lateral that flooded her home in 2016. Photo by Allison DeHart

All the houses on Cornelius Drive flooded, recalls Pam Suire, a homeowner on the street in Quail Hollow, one of the heaviest hit Lafayette neighborhoods in the flood of 2016. Water crested over the eroded banks of the Isaac Verot Coulee behind her house and rose up from the street drains in her front yard, making her house an island. Suire and her family escaped the waters on Friday, returning to their home of 17 years after the water receded on Sunday. Her daughter stayed behind over the weekend with the Suires’ dogs and cats in a house waterlogged by 14 inches of floodwater and the power shut off. They marooned themselves on the furniture to stay dry.

“She wouldn’t leave the animals. We couldn’t find anyone to come rescue her with the animals. If I really thought that the house was gonna flood that way, I would have gone and dragged her out,” Pam Suire says.

Nearly two years on, the Suires’ dining room is still under reconstruction, the last remaining bit of ongoing repairs that Suire and her husband John have taken on themselves in their spare time. The dogs pick at fruit in her backyard, running around a lawn pockmarked with divots and soggy soil.

In November 2017, the water rose within inches of soaking her house again. That’s two major flood events on her street, just more than a year apart. Until the flood of 2016, her home had not taken on water since they moved to the house in 2000.

More than 350 houses in and around Suire’s neighborhood flooded in 2016, according to data provided by Lafayette Consolidated Government. Most of those houses are inside a 100-year flood zone.

Homeowners like the Suires continue to await drainage work promised in a tax rededication passed last year. City-parish government developed a drainage action plan to prioritize and distribute the dollars raised in the new tax measure, a signature policy proposal developed by Mayor Joel Robideaux’s administration in response to the flood of 2016. For the most part, the plan is billed as catch-up on “deferred maintenance,” a slog through miles of unkempt coulees.

Robideaux’s rededication moved $9.5 million in one time money to a drainage fund and created a millage that generates roughly $2.5 million a year. That scratches the surface of a problem decades in the making. The administration says it could take as much as $31 million to work down the metastasized maintenance backlog.

Meanwhile, LCG’s action plan estimates a sufficient overhaul of the system could cost between $500 million and $875 million.

The drainage action plan is not a fix; it’s a Bandaid. It prioritizes limited dollars to a limited batch of cleanup projects that will restore, as much as possible, the parish drainage system’s designed functionality. To be clear: The drainage action plan, once complete, would not prevent another 2016 flood. Nor is it intended to.

So how does the drainage action plan work?

The crux of city-parish government’s plan is a matrix rating system devised to prioritize 77 maintenance projects selected from around the parish. That’s roughly 100 miles out of a total 850 miles of unimproved channels managed by LCG’s Public Works Department. Based on ratings, the projects are sorted into two basic categories. The first 27 projects — listed as Priority A — will be tackled with the $9.5 million currently available. The remaining 50 — Priority B and then some — will have to wait until more funding becomes available.

A look inside the matrix

Projects are evaluated on eight criteria selected, according to Fred Trahan, the Public Works engineer in charge of the drainage action plan, to ensure that priorities are set without bias. Here’s the list of criteria:

  • Addresses in the drainage basin
  • Percentage of the basin in a flood zone
  • # of FEMA claims outside of a 100-year flood zone
  • # of FEMA claims inside of a 100-year flood zone
  • Repetitive loss properties
  • Cost of improvement per address
  • Difficulty getting in and getting out
  • Difficulty of obtaining necessary permitThe criteria are then weighted to favor some factors over others. The percentage of the drainage basin in a flood zone — i.e. how flood prone the area served by a coulee is — scores up to 10 points. So do the number of repetitive loss properties — i.e. the number of houses that have flooded more than once — and the cost of improvement per address. The cheaper the cost per address, the higher the score. The rest of the factors can score up to five points each.

An example:

The lateral of Isaac Verot Coulee behind Pam Suire’s house scored 34 points out of a possible 55 points. LCG estimates the project would cost $360,000 to complete. With nearly 1,900 homes in the drainage basin, the project would cost $195 per address. That scores an 8 out of a possible 10 points. In other words, a big factor in this project’s priority is how much bang the city gets for its buck. Here’s how the rest of the tally adds up:

Work behind the Suire home would involve otherwise routine drainage maintenance. Crews will clear fallen branches and other debris from the cluttered channel and haul it out in a truck. Trahan says work crews will need to remove silt and soil and that’s piled along the banks over the years, a more labor intensive process that requires environmental permitting.

But the insurgent flooding that Pam Suire has suffered may not be remedied by the work planned. When she and her husband first moved into the neighborhood, Pam Suire says, Cornelius Drive would flood over, but the water wouldn’t reach her house. About ten years ago, detention ponds were built along the extension of Camellia Boulevard to accommodate new developments. The ponds dried up the streets after heavy rains, she notes, until Parc Lafayette was completed in 2010. Now, she says, the streets flood once again.

Geologist Gary Kinsland, whose mother-in-law lives across the street from the Suires, walked the coulees after the 2016 flood. He says the coulee can’t handle the added volume of water shedding into it. He and a colleague at UL Lafayette modeled the 2016 flood after the fact and found that, even if the coulee lateral behind the Suire’s house was operating at full capacity, Quail Hollow would have flooded.

“Quail Hollow is a bowl,” Kinsland says. To avoid flooding, he says the coulee needs to be widened, not cleaned up. It’s a low area already prone to flood, which is why many of the houses are built on dirt mounds. Impervious surfaces from nearby development can make normally “excusable” rain events into flood risks, he says. Without major improvements to the narrow, cluttered portions of Isaac Verot Coulee behind it, it’s unable to accommodate rain events, Kinsland maintains.

What’s the point of all this data?

That’s, of course, the pertinent question. Robideaux has messaged this effort as a means of rebuilding public trust. At $2.5 million per year, that’s an expensive trust fall. But against the backdrop of hundreds of millions of dollars in needed improvements, it remains a pittance.

What’s most striking about the drainage matrix is not what it includes, but what it doesn’t. The matrix does not evaluate any expected outcomes. That is to say, the matrix doesn’t include among its factors how effective any given project will be.

Arguably, that’s a value judgment not readily quantified. No hydraulic modeling is available to measure the program’s impacts. But the plan is designed on a series of value judgments, anyhow. How difficult it is to get trucks in or out is a value judgment. How difficult it will be to get permits is based on past experience. In fact, the entire plan runs on the reasonable assumption that restoring coulees to their original functionality would have only a “marginal increase” of water downstream.

Theoretically, at least, clearing the coulees up stream would pose a risk to homes downstream and closer to the river. LCG’s plan concludes that restoring the coulees to normal function shouldn’t cause substantial down river impacts. That’s a judgment call.

In any case, the plan does, at times, consider some expected outcomes. The plan’s highest scoring project, along the main channel of the Isaac Verot Coulee, tallied a cumulative rating of 44. The area served has 14,000 homes in it, roughly 10 percent of which flooded in 2016. Twenty-one houses have flooded more than once.

But LCG estimates the necessary improvements would cost $1.7 million, most of the annual revenue accrued from rededicated funds. Even at that price tag, the project would not “greatly improve channel performance,” according to plan notes. Thus, the project was downgraded to “debris removal only” — a manageable $150,000 budget item. Three other projects were similarly downgraded. Significant improvement on these channels would require a major overhaul, the sort of project figured into the $500 million to $875 million price tag for constructed improvements.

Weather permitting

“We have flood insurance now,” Suire says. Her house is not in a flood zone, although she and her husband kept flood insurance for the first few years they lived in the house. They are one of 81 Quail Hollow area households outside of a flood zone to make a FEMA claim in 2016. They let the insurance go when bills got tight years later, deciding they were safe enough to not to bear the expense.

The Suires have spent $90,000 out of pocket putting their house back together. That price tag doesn’t include the assistance they got from their church, the state and some nonprofits.

Work related to the drainage action plan is beginning to come online. Trahan expects that eight of the projects will be complete by the end of October: Four concrete lined coulees will be scraped of silt and accumulated dirt. Four more, including the top rated Isaac Verot Coulee project mentioned before, will be cleaned only of debris like branches and trash.

Three projects have been shifted into ongoing drainage work outside of the action plan, Trahan says. The remaining 16, including the coulee behind Pam Suire’s house on Cornelius Drive, are trickier and require environmental permitting to complete. Around 50 percent of the 40 miles of coulee in this group have been surveyed for work. He expects, weather permitting, that these projects will be finished in the beginning of 2019.

“If I could see them do something, work-wise,” Suire says, she would feel more comfortable with what remains a precarious situation.

After the November 2017 scare, Pam Suire says she reached out to the city to take a look at the coulee behind her house. A Public Works rep told her he walked the coulee himself and found no blockage.

Since then, the Suires have continued to work on their house. They watch warily when the rains get heavy and worry about how high the water will rise.

“Every piece of flooring in the house is now vinyl,” Suire says. “I’m not taking any chances.”