River rising, expected to top flood stage
Published 12:00 am Thursday, May 7, 2009
It’s late in the season, but high water is on the way.
The Mississippi River is forecast to top flood stage of 43 feet at Vicksburg next week. Spring rises, largely due to snow melt, are usually over and done by this date on the calendar.
The Mississippi River
Today at Vicksburg: 38.3 feet
Crest forecast: 43.5 feet on May 19
Flood stage: 43 feet
“They started discharging water out of the Barkley and Kentucky dams (near the Tennessee border), and that in turn affected our forecasts for Cairo and cities further south,” said Kai Roth, senior hydrologist with the river forecast center in Slidell. “There’s water coming out of tributaries flowing into the Tennessee and Cumberland rivers, and they’re passing water out of that system.”
This morning, the river at Vicksburg stood at 38.3 feet, a rise of .9 foot in a 24-hour period. The National Weather Service increased its forecast crest for Vicksburg by 1 1/2 feet and pushed the crest date back to reach 43.5 feet on May 19 based on rain models for the next 24 hours. Roth said the forecast could be ratcheted up again.
“Any additional rainfall in the upper Mississippi or Ohio River valleys could cause the crest to increase,” he said.
The forecast center revises its forecasts twice daily. Cairo, Ill., a benchmark for rises and falls in the Mississippi River south of the city, is forecast to begin falling after a Saturday morning crest of 48.5 feet — 8.5 feet above flood stage at the city.
Flood stage at Vicksburg was last topped on March 29, 2008, with the Mississippi River eventually cresting at 50.9 feet on April 21 and receding below flood stage on May 10. It was the highest measured river stage recorded at the city since 1973, when the river topped out at 51.6 feet.
As readings approach flood stage, some low-lying roads north and south of the city become impassable. At the forecast crest, no structures should get wet and the impact on farm fields will be minimal.
In 2008, Vicksburg emergency management officials estimated at least 145 residents were displaced from 101 homes in the city. Since then, 16 homeowners in the Ford and Waltersville subdivisions have agreed to federal buyouts of their homes. Meanwhile, some flood victims who lived in repetitive flood plains north of Vicksburg waived their rights to any future federal disaster assistance in March in order to have their utilities restored to begin repairing damage. An estimated 50 homes were deemed “substantially damaged” by the city during last year’s flood, “substantial” being defined as damage requiring repairs costing 51 percent or more of the home’s pre-flood value.
Many roads in the city and county north and south of Vicksburg went under water as well during flooding in 2008, including LeTourneau Road, which caused the off shore oil rig manufacturer to run on a skeleton crew for five weeks. Portions of Mississippi 465 were closed for more than a month. Intense river currents caused four barges to slam into the U.S. 80 bridge at Vicksburg in a 10-day period and a number of other barge breakups, leading the U.S. Coast Guard to temporarily restrict the times when vessels could pass beneath the bridge.
The high river stage also forced the gates of the Steele Bayou Control Structure north of Vicksburg on Mississippi 465 — the lone drainage point for 4,093 square miles of levee-locked land known as the Yazoo Backwater Area — to be closed for nearly two months.
The structure was closed on March 13 and reopened on May 8, 2008, at which point the water stage inside the structure was 92.1 feet and the U.S. Army Corps of Engineers estimated a total of 344,000 acres of forest and farmland in the backwater area were flooded. The gates are closed when the river side water stage of the structure is higher than the land side, and can be reopened only when the river side stage falls below the land side stage.
As of Wednesday afternoon, the river side stage was at 85.7 feet and the land side stage at 85.4 feet, said Waylon Hill, civil engineering technician in the Corps’ water division.
“We have had some significant rainfall over the backwater area in the past week. We had 5 inches fall on Sunday and about another 3.5 (on Wednesday). The gates are still open now, and we want to let as much of that water run out as possible,” said Hill. “We’re in a wait and see mode until the river rises beyond the land side stage — and that may not happen at all.”
*
Contact Steve Sanoski at ssanoski@vicksburgpost.com