An 850-foot “spur dike” that juts out from the intersection of the 28-mile backwater levee and the Mississippi River mainline levee just south of Eagle Lake is being credited for keeping the Yazoo Backwater Area dry during the river’s historic flood this spring.

“Some engineer back in the ’40s — with his pocket protector, his slide rule and big, thick glasses — said, ‘We need to put a spur dike right there,’” Lt. Col. Greg Raimondo said Wednesday. “And they did. And that kept the water from overtopping the backwater levee.

“It was kicking the water back to the middle of the river,” Raimondo told the Vicksburg Lions Club Wednesday as he highlighted the Corps’ successes during the historic flood and funding challenges next fiscal year. “It was an amazing thing, like an archeological find, when they came across it.”

A 4-mile blanket of polyvinyl sheeting was laid atop the levee to prevent rising water from shaving the levee during the river’s rise to its historic 57.1-foot crest. The material will be removed, then thrown away or recycled by year’s end, Corps officials have said.

The sheeting and absorbent sand bins used to shore up the intersection of levees cost about $2.5 million to put into place, according to the Corps. Still, stages on the river side of Steele Bayou measured by the district’s hydraulics unit read a foot lower than levels for which they’d prepared — for a reason, Raimondo said.

Many of the nearly 4,100 square miles of land in the backwater area are used for farming. Filling low spots on the 28-mile earthen barrier so it’s 107 feet above sea level from end to end is one of three improvements planned by the District. Construction of a 1,700-foot berm and 30 relief wells on the mainline levee at Buck Chute is funded and scheduled to begin in the fall. A section of levee at Lake Albermarle is slated to be raised and reinforced where about 300 feet slid away during the flood, though a time schedule for the work is undetermined.

For fiscal 2012, the Corps expects about $100 million less than this year systemwide. For the Vicksburg District, which covers half of Mississippi, northern Louisiana and southern Arkansas, total funds will equal $122.4 million, nearly $15 million less than this year.

Funds for the Mississippi River and Tributaries Project, begun after the 1927 flood to reinforce river banks and raise levees, total $82.5 million for the coming year, about $10 million less than 2011, according to figures compiled by the Mississippi Valley Division and part of Raimondo’s presentation.

“We haven’t seen a supplemental (allocation),” Raimondo said. “We’re going to have to do the fixing in the Mississippi Valley Division with the funding we already have.”

Cost to fully rebuild and repair the system overseen by the MR&T have been pegged at between $1 billion and $2 billion.