Assuming the flying lasers stay on schedule, Louisiana should have new flood data by April.
After last summer's catastrophe, officials began putting some muscle into efforts to better understand, predict and prepare for Mother Nature. That includes the state's Department of Transportation and Development, which contracted a firm to make a new model of the Amite River Basin where much of the flooding occurred.
Thursday, they gathered with fellow engineers to discuss their progress, as well as to receive updates from crews doing similar work at the local level.
Over the past several months, Bob Jacobsen has been evangelizing for science.
The state's team has been poring over survey data and engineering studies. Over the winter, they plan to send out aircraft equipped with lasers to scan a swath of the basin, which covers most of the capital area on the east bank of the Mississippi River. The modeling area will include 1,200 miles of creeks, rivers, bayous and canals, said Sam Crampton, Associate Vice President of the Dewberry engineering firm.
After the 2016 flood devastated the region, the U.S. Geological Survey and the Amite River Basin Commission collected high water marks to chart the extent of the flooding. Engineers will use that information to see how far and deep the water spread during what was an especially destructive storm.
After major flooding in 1983, the state prepared to dig the Darlington Reservoir along the St. Helena-East Feliciana parish line and hired the firm Forte & Tablada to study the basin. The reservoir was never built, but Thursday staff at the firm said they were going back and comparing the data they gathered then with current conditions to see how features like the Amite River have changed in the intervening decades.
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Using weather, statistical, risk assessment and hydrological software, the team can determine which areas are most at risk and recommend which infrastructure projects will return the biggest bang for their buck. Crampton said it would be the "framework" for assessing the impacts of new flood infrastructure and land use plans.
An overly simplified way to think of it would be to imagine a grid over the parish. Engineers use weather data to simulate a storm and, given the contours of the land and the existing flood control measures, they see which grid boxes flood. Then they'd run the experiment over and over to simulate years of weather and look which squares flooded the most. If they're already wetlands it may be of no concern, but if they're subdivisions, a new pump station, canal or other project may be worth building.
Bob Jacobsen, an engineer who contracts for the Basin Commission, compared it to movie magic employing computer generated imagery.
"Just as CGI dinosaurs and space ships are rendered with complex software to be very realistic, so hydrologists use sophisticated programs to provide very detailed and physically accurate depictions of the extent of floods and the impact of potential changes. Both types of artificial mimicking are also similar in that they require the most advanced computers and huge amounts of data," he explained.
The state isn't the only one at work. Other groups shared their work Thursday on several local projects.
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In East Baton Rouge and Ascension parishes, contractors are preparing stormwater management plans to help politicians decide where to invest in new levees or pumping stations or other infrastructure.
Louisiana will receive more than a a quarter-billion dollars in federal infrastructure funding from last summer's flood alone. The state model will also help decide how to spend the money, as well track how changes to the floodplain — including new development — will affect how water moves during a storm.
Authorities know that new buildings displace water that can have an impact locally or even regionally, but "we had no way of determining what that impact was," said Chris Knotts, chief of DOTD's public works and water resources division.
Last summer emphasized how important it is to better understand the floodplain and protect the people who live within it.
"The 2016 flood changed out mindset. It's a paradigm shift," said Atri Sen, senior project manager for engineering firm HNTB, which is preparing the parish plans.
"I think we have to make some very, very hard choices," Sen said. "We cannot do what we have done, and the 2016 flood exposed this. ... Things are changing, sands are shifting."
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By the first quarter of 2018, Sen expects to have sixty percent of his territory ready for planning purposes. By that, he means he'll be able to predict the effect of dredging a river or otherwise altering the water system.
In addition to Ascension and East Baton Rouge, his firm is looking at parts of other parishes that are hydrologically tied to them, including much of Livingston, but also the Felicianas and as far as St. Helena.
The city of Central will have its own new system up and running for the public by next summer, said John Storm, a U.S. Geological Survey hydrologist.
The end result will coordinate with weather predictions in real time, so if a tropical storm or other rain system is on its way the model will take the meteorological data and predict which areas of the Amite and Comite Rivers will flood. As such, it's less a planning tool than an emergency response guide, Storm said.
He expects it will allow residents to see if their houses are likely to flood and which roads will wash-out should they choose to evacuate. First responders will also get a heads up where to look for victims and where to stage so they'll be in the best position to lend help.
The next time a flood threatens, residents in Central plan to be the first to know.
When it's done, the Central model will be the first of its kind in Louisiana, though they're popular elsewhere in the country, like the Midwest. Hattiesburg, Mississippi has the closest version, which Storm also created.
Much of the conversation on Thursday was technical, in part because engineers want their colleagues to be able to augment their work. The DOTD model will become publicly available upon launch.
When engineers perform drainage studies, as is done when developing a new shopping center or subdivision, the state will review their findings and consider incorporating them into the model to see how new houses, stores and parking lots are impacting the system at large.
"People ask me, 'Oh, Dietmar, how do we eliminate flooding?' You have to talk to Mother Nature about that," said Dietmar Rietschier, executive director of the Amite River Basin Commission, which hosted Thursday's event.
"You need to allow Mother Nature to have space to put the water somewhere. ... Modeling is wonderful, but it is a tool," and needs to be incorporated into local and regional planning, he continued.
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