Computer modeling that indicated a tremendous amount of rain could fall on the Capital region two years ago this month seemed so out of line with anything that had happened before that forecasters dismissed the numbers rather than heed their warning, a television meteorologist said Monday at a symposium assessing the storm.
“We should have given this (model) more faith and attention than we did,” WAFB meteorologist Jay Grymes said.
As they poured rain over the Gulf of Mexico, the storms received little attention even though forecasts showed the deluge could continue inland, Grymes said. He said TV weathermen could have done a better job warning the public about the storm _ and at least should have warned first responders about the potential for the tremendous amounts of rain.
More than 2½ feet of rain fell on some parts of the Amite and Comite river basins, generating flooding that swamped portions of East Baton Rouge, Ascension and Livingston parishes. The flood level was unprecedented.
“It completely blindsided me. I had no idea it was coming," said John Johnston of the Louisiana Geological Survey. He said if anyone had told him that the Amite River would reach the levels it did, "I would’ve laughed at you.”
Monday's symposium at LSU was sponsored by the Louisiana Geological Survey and the Baton Rouge Geological Society. Presenters addressed what worked, what didn't and what needs to be done before the next catastrophe.
Scientists and engineers packed an LSU conference hall Wednesday for a post-mortem on the August flood.
WBRZ's Josh Eachus has been examining the psychology of disaster warnings. He told fellow meteorologists that they too often speak in jargon and rely too much on describing the destructive potential of high winds, storm surges and the like instead of telling their audience what to do. If a meteorologist wants viewers to evacuate to higher ground, they need to indicate where that higher ground is located, he said.
To emphasize his point, Eachus displayed some of the most popular tweets from the early days of the flood. They showed photos and videos of well-known corridors and portrayed scenes like cars being flooded, which showed the human impact of the storm. Those are the kind of messages that can convince people to take precautionary action, he said.
Grymes also faulted the media for repeating the federal government's assertion that 2016 represented a 500-year or 1,000-year event. Those designations are misleading at best and dangerous at worst if they lull people into a false sense of security. It's "not even close" to call 2016 a 1,000-year event," the meteorologist said. Records only go back about 100 years, and the 1,000-year designation can be confusing because if the same storm happened again but 15 miles to the north, it would have the same affect on places like Livingston and Ascension Parishes, yet that event would count differently toward determining flood frequency, Grymes said.
Without going into too much detail, several speakers warned against putting more concrete and development into the floodplain where it can displace water during a rain event.
"This event is not a totally natural disaster," said consulting engineer Bob Jacobsen, who has done work for the Amite River Basin Commission.
Two years after a flood ravaged the capital region, construction of new homes proceeds in much the same way.
The floodplain is constantly changing, and it's not all because of new strip malls and subdivisions. LSU hydrology professor Jun Xu has been surveying the confluence of the Amite and Comite River since the flood and compared his findings to aerial photographs taken in 2002. The confluence is near the U.S. 190 bridge, which gives a handy point of reference to see how the water has changed. A large portion of the east bank has eroded, while the west bank has silted in. Even more arresting — the rivers join about 180 feet farther downstream than they did just 15 years ago, scouring the banks near the bridge supports, Xu said.
Jacobsen and Amite River Basin Commission Executive Director Dietmar Rietschier repeated their call for basin-wide agencies to guide policy across the state rather than in a piecemeal fashion by parish governments. Rietschier's own group technically has the authority — but not the funding — for such a task.
The U.S. Geological Survey shared some good news. Its staff has teamed up with the city of Central to create a tool that will let residents and first responders know how high flood waters will reach as a storm bears down. Authorities have said it will help guide evacuation and relief efforts, as well as let people know when they don't have to worry. USGS hydrologist John Storm showed a preliminary map and said the model will be publicly available "in the next few months."