Army Corps delays opening of Morganza Spillway once more

John Dupont
The Morganza Spillway

The U.S. Army Corps of Engineers has one again postponed the opening of the Morganza Spillway, although local and state authorities remain steadfast in preparations for an opening.

The Corps now plans to open the structure Sunday, June 9. The original date was set for June 2, but uncertainty on water flow north of the state prompted officials to table the opening until June 6.

Current river forecasts have been lowered by a half-foot, which prompted the latest delay by the Corps.

An opening of the Spillway would mark the first since May 14, 2011 and only the third since completion of the structure in 1954. The Corps first opened the spillway in 1973 in the wake of severe flooding throughout the central states.

The Bonnet Carre' will continue to operate over the next month.

The Atchafalaya River will rise 1 to 3 feet over the next several weeks, according to the National Weather Service.

Forecasts over the next two weeks show rainfall of 2 to 5 inches over portions of Arkansas, Mississippi, Tennessee and Missouri. The Lower Mississippi River could see slightly higher levels from Cairo, Ill., downstream to Helena, Ark.

Elevated stages would dampen the rise as it approaches the junction of the Arkansas River, and high water levels would remain in the forecast into July.

The delay comes as areas along the Louisiana coast have already braced for an additional deluge from the Midwest flooding.

Overtopping, levee breaches and storage on the Arkansas River has caused less flow to make it into the lower Mississippi River. Morgan City is now forecast to crest at 9.5 feet by the third week of June, which will mark the third highest crest on record and the highest since May 2011.

Crest heights were reduced six inches from Arkansas City, Ark., downstream to Natchez, Miss. The Red and Ouachita rivers continue to for the second week of June. Uncertainty persists on the eventual peak flow/timing from the Arkansas River and how that will ultimately impact the lower Mississippi River.

The Upper Mississippi River continues to rise, and major flooding is occurring at Cape Girardeau, Mo., and Thebes, Ill. Additional rises of 1 to 2 feet are expected over the next few days.

Flows along the Upper Mississippi River, combined with more moderate rises along the Ohio River, will lead to a crest of 47.5 5 on Saturday, June 8 – nine feet lower than the March flood. The crest will approach the junction of the Arkansas River within two weeks and fill in behind the crest of the Arkansas River.