The Great Flood of 2011 (Part VIII)

• 

• U.S. NEWS
• MAY 14, 2011, 7:12 P.M. ET

Louisiana Floodgate Opens, Diverts Mississippi

Associated Press

People watched as water diverted from the Mississippi River spilled through a bay in the Morganza Spillway in Morganza, La., on Saturday.

MORGANZA, Louisiana—A steel, 10-ton floodgate was slowly raised Saturday for the first time in nearly four decades, unleashing a torrent of water from the Mississippi River, away from heavily populated areas downstream.

The water spit out slowly at first, then began gushing like a waterfall as it headed to swamp as much as 3,000 square miles (7,770 square kilometers) of Cajun countryside known for small farms and fish camps. Some places could wind up under as much as 25 feet (7.5 meters) of water.

Opening the Morganza spillway diverts water away from Baton Rouge and New Orleans, and the numerous oil refineries and chemical plants along the lower reaches of the Mississippi.

Louisian Opens the Floodgates

Getty Images

Inmates from the St. Martin Parish Correctional Center help residents fill sandbags in Butte LaRose.

"We're using every flood control tool we have in the system," Army Corps of Engineers Maj. Gen. Michael Walsh said Saturday from the dry side of the spillway, before the bay was opened. The podium Walsh was standing at was expected to be under several feet of water Sunday.

The Morganza spillway is part of a system of locks and levees built following the great flood of 1927 that killed hundreds. When it opened, it was the first time three flood-control systems have been unlocked at the same time along the Mississippi River.

Earlier this month, the corps intentionally blew holes into a levee in Missouri to employ a similar cities-first strategy, and it also opened the Bonnet Carre spillway northwest of New Orleans to send water into the massive Lake Ponchatrain.

Snowmelt and heavy rain have been blamed for inflating the Mississippi, and the rising river levels have shattered records all set 70 years ago.

About 25,000 people and 11,000 structures could be in harm's way.

In Krotz Springs, Louisiana, one of the towns in the Atchafalaya River basin bracing for floodwaters, Monita Reed, 56, recalled the last time the Morganza was opened in 1973.

"We could sit in our yard and hear the water," she said as workers constructed a makeshift levee of sandbags and soil-filled mesh boxes in hopes of protecting the 240 homes in her subdivision.

Risk Levels

See the latest data from flood gauges throughout the Midwest and South.

• More photos and interactive graphics

Some people living in the threatened stretch of countryside—an area known for a drawling French dialect—have already started heading out. Ms. Reed's family packed her furniture, clothing and pictures in a rental truck and a relative's trailer.

"I'm just going to move and store my stuff. I'm going to stay here until they tell us to leave," Ms. Reed said. "Hopefully, we won't see much water and then I can move back in. "

It took about 15 minutes for the one 28-foot gate to be raised. Several hours will pass before any of the water hits sparsely populated communities. The corps planned to open one or two more gates Sunday in a painstaking process that gives residents and animals a chance to get out of the way.

The water will flow 20 miles south into the Atchafalaya Basin. From there it will roll on to Morgan City, an oil-and-seafood hub and a community of 12,000, and eventually into the Gulf of Mexico.

The Krotz Springs area was in a sliver of land about 70 miles long and 20 miles wide, north of Morgan City, and could get water in about 12 hours. The finger-shaped strip of land was expected to eventually be inundated with 10- to 20-feet of water, according to Army Corps of Engineers estimates.

The water wasn't expected to reach Morgan City until around Tuesday.

Engineers feared that weeks of pressure on the levees could cause them to fail, swamping New Orleans under as much as 20 feet of water in a disaster that would have been much worse than Hurricane Katrina in 2005.

Opening the Morganza should help refiners along the river, including ConocoPhillips, Exxon Mobil Corp., Marathon Oil Corp., Murphy Oil Corp., and Motiva Enterprises LLC, a joint venture co-owned by Royal Dutch Shell PLC and Saudi Aramco. About 14% of U.S. refining capacity is located on or near the banks of the Mississippi River.

Rising waters forced Exxon to cut production at its 504,000 barrels-a-day Baton Rouge refinery by at least 50,000 barrels a day and possibly 100,000 barrels a day, a person familiar with the situation said Friday. The company also shut in some crude oil pipelines serving the refinery

Exxon Saturday said it had closed the docks at the facility because of the flood.

"Despite the shut down, the complex continues to operate and product products," Exxon spokesman Kevin Allexon said.

Diverting water through the Atchafalaya will create problems for oil and gas producers and at least on refiner to the south of Baton Rouge, however.

The Louisiana Department of Natural Resources Office of Conservation estimates that 2,264 wells lie in that area and would be inundated if the Corps of Engineers carries out its plans. Those wells produce the equivalent of 19,278 barrels of oil per day-about 10% of the state's onshore production, the state agency estimated.

The Corps employed a similar cities-first strategy earlier this month when it blew up a levee in Missouri—inundating an estimated 200 square miles of farmland and damaging or destroying about 100 homes—to take the pressure off the levees protecting the town of Cairo, Ill., population 2,800.

The disaster was averted in Cairo, a bottleneck where the Ohio and Mississippi rivers meet.

Video

• Watch the spillway video feed.

This intentional flood is more controlled, however, and residents are warned by the Corps each year in letters, reminding them of the possibility of opening the spillway, which is 4,000 feet long and has 125 gate bays.

The spillway, built in 1954, is part of a flood plan largely put into motion in the 1930s in the aftermath of the devastating 1927 flood that killed hundreds.