FLOODWALL CAN HOLD 54-FOOT RIVER STAGE

Cape Girardeau's floodwall is designed to hold back a Mississippi River flood of 54 feet on the Cape Girardeau gauge.

C.A. "Andy" Juden of the Main Street Levee District said the wall is in no danger of collapsing under pressure of the swollen river.

"There is no reason to have any concerns about the seawall," Juden said. "Actually, the wall gets stronger as the river goes up. There is a footing for the wall that goes way out into the river. The weight of the water adds to the structural integrity of the wall."

The south gate of the floodwall is being closed this morning, the first time in 10 years.

The south gate is designed to be closed when the river reaches 46 feet, but Juden said the wall will be closed before the river reaches that level. The railroad already has stopped operating.

"When we close that gate, then the whole levee district is sealed at that point," he said.

Part of the flood-control project is a pumping station, which forces city ground water out into the river during floods. Juden said the pump is staying way ahead of ground water and seepage from the flood. It pumps 75,000 gallons a minute, and Juden said the pump could continue working even if floodwaters came over the top of the wall.

The Army Corps of Engineers announced plans for the flood-control project, which included the concrete floodwall, in February 1955.

The wall is built to keep out water at 51 feet on the gauge, with 3 feet of freeboard. That means full protection is provided downtown Cape Girardeau at 51 feet, with the additional 3 feet to keep back waves. For all practical purposes, it is designed to protect against a 54-foot flood.

Planned in three sections, only one section (consisting of Reaches 2A and 2B, as designated by the Corps) was designed in detail in 1955. No other sections, including any in part of the Red Star suburb or the area from the bridge south past what used to be Smelterville, were designed because economic justification for them was not established.

Reaches 2A and 2B protect land along the Mississippi from Sloan's Creek to just past the traffic bridge. It uses a system of earthen levees, combination earthen levees and concrete walls, and an inverted T-wall.

The earthen embankment starts at Chestnut Street at the north, follows the south bank of Sloan's Creek to the mouth of that tributary, and then follows the course of the railroad tracks. In the first section, the earthen levee rises 20 feet high and has a base of 130 feet. At a point near the power plant, it changes to a concrete wall 300 feet in length along the river.

An earthen levee continues south 1,000 feet to a point at the end of Mill Street; it averages 21 feet in height from the ground and has a base of 160 feet in width. From Mill Street, the levee for the next 1,700 feet is a combination of earth and concrete.

The dirt section is about 12 feet in height and the concrete section 8 feet, making the overall height 20 feet. This I-wall was placed on a sheet piling base and is 12 inches thick. Terminus for the combination embankment is about 300 feet north of Bellevue.

At that point, an inverted T-type concrete wall takes over; it runs 4,000 feet to the bridge. The wall rests on a wide base sunk into the ground to a depth of from 4 to 5 feet, or to rock where it was encountered. The concrete barrier is 18 inches thick at the top, and on the river side it is backed up with revetted earth for a distance of a few feet.

The concrete section averages 15 feet in height until it passes the foot of Broadway. At Themis it measures 20 feet in height; at Independence 20 feet; at Merriwether 19; at William 13; at Good Hope 8; and at the bridge 7. The varied heights were dictated by varying topography.

The design included the two pumping stations and a system of pressurized sewers. The plans provided for two openings in the wall along the business area, one at Broadway and the other south of the bridge. Those plans were altered slightly in 1958, when the Corps allowed for a another opening in the floodwall at Themis.

On Oct. 22, 1964, the 4,000-foot concrete floodwall, along with the earthen levees to the north and south, were dedicated. The concrete section itself cost more than $600,000; the whole flood project cost more than $4,750,000.