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Barry Takes Aim, Threatens Dangerous Rain and Surge for South Louisiana

What many have feared for months is unfolding on the Lower Mississippi River, with Tropical Storm Barry approaching South Louisiana while the river is at flood stage.

As of the National Hurricane Center’s 10 a.m. advisory (July 12), Tropical Storm Barry was located 100 miles southwest of the mouth of the Mississippi River and moving west-northwest at 5 mph. The forecast track from the National Hurricane Center predicted Barry will make landfall west of Morgan City, La., near New Iberia as a minimal Category 1 hurricane the morning of July 13. The National Weather Service warns that rain totals could reach 20 inches or more in spots as the system slowly moves inland.

Barry formed when a weather system from the north moved through Georgia and the Florida Panhandle into the Gulf of Mexico. Once over the 85-degree water of the Gulf, the area of low pressure slowly developed a center of circulation and was finally classified as a tropical storm in a 10 a.m. notice from the National Weather Service on July 11.

Forecasts ahead of landfall called for rainfall totals of 20 inches or more in some places. The National Weather Service had initially predicted a 3-foot rise up to 19 feet on the Mississippi River at the Carrollton gage in New Orleans due to winds out of the south and Barry’s storm surge. However, forecasters revised predictions to 17 feet—flood stage in New Orleans—as Barry struggled to push a surge up the river. The levee near at the Carrollton gage stands at about 20 feet.

By the morning of July 13, the Carrollton gage had already seen a slight rise and fall to around 16.6 feet. The National Weather Service forecasts the river to rise to just over 17 feet on July 15 as rainwater from Barry makes its way downriver.

Joaquin Mujica, deputy chief of operations division for the New Orleans District, echoed what waterway managers have been saying for months: this is a year unlike any other. As of July 12, the Mississippi River in New Orleans had been in flood 257 days, with 150 of those at 15 feet or higher. Mujica said the Corps is monitoring 306 sites on the river with sand boils or seepage.

“These levees are under a tremendous amount of stress,” Mujica said.

Mujica said the Corps was prepared to deploy HESCO baskets to lower points in the river levee or sandbags at floodgates if conditions called for that.

Elsewhere on the system, the New Orleans Engineer District closed the Harvey Canal Lock the morning of July 11 and began placing stop logs in the lock to mitigate the anticipated rise in the river. With the Coast Guard enacting the area’s East and West RNAs (regulated navigation areas), the Corps spent the day July 11 locking vessels from the east through the Inner Harbor Navigation Canal Lock (IHNC). The IHNC Lock closed about 9 p.m. July 11, with the Corps welding steel plates to the top of floodgates to provide extra freeboard. About the same time, the Southeast Louisiana Flood Protection Authority-East closed the Lake Borgne Surge Barrier, the Bayou Bienvenue sector gate and the Seabrook floodgate, essentially closing the system from the east. Likewise, flood protection officials closed structures on waterways to the west.

By July 12, Jefferson Parish had already declared a mandatory evacuation for southern portions of the parish. Plaquemines Parish has mandated an evacuation of the parish’s east bank community, along with communities south of the floodgate across LA-23 in Oakville on the west bank of the river.

River pilots associations conducted the final ship movements in and out of the river July 10. The Associated Branch Pilots, charged with bringing ships from the Gulf to Pilottown, said they are keeping a small crew in southern Plaquemines Parish throughout the storm. As of July 12, the Crescent River Port Pilots, who bring ships from Pilottown to New Orleans, remain busy resetting ships’ anchors as needed.

The Coast Guard plans to issue Port Condition Zulu sometime Friday, July 12, essentially closing the Mississippi River south of the Sunshine Bridge. Coast Guard officials to the west of New Orleans declared Port Condition Zulu for Houma, Morgan City, Fourchon, New Iberia, Lafayette and Intracoastal City at 10 a.m. July 12.

Coast Guard officials from Sector New Orleans are urging operators to avoid any vessel movements on the Mississippi River—except when responding to emergencies—in order to protect levees from wave action.

At Morgan City, nearer to where Barry is expected to make landfall, the National Weather Service anticipates a rise on the Atchafalaya River from just above 7 feet to 9 feet, with a fall below 8 feet by late in the day July 14.

 

* Note: This article was updated July 13 to reflect current forecasts.

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