Drought conditions in the North keep river levels low in the SouthPublished 12:05am Saturday, July 7, 2012
VIDALIA — Even as Mississippi River levels continue to fall, experts say the low levels aren’t worrying them as much as the time of year they’re occurring.
On Friday, the river level at Natchez was 11.9 feet. The National Weather Service lists the record low was -2.70 feet on January 1930.
The gauge at Natchez measures water surface elevation, not depth, below or above sea level of 17.28 feet.
When the river levels fall below that particular measuring point, the readings are listed as negative, meaning they are below the 17.28 feet sea level.
That system of measuring was put in place at Natchez before gauges were able to output more than three digit numbers, said Drew Smith, a hydraulic engineer with the U.S. Army Corps of Engineers.
And while the low water levels are something the Corps of Engineers keeps an eye on, Smith said the only rarity of the low levels is the time of the year.
“The problem is not how low the river is, it’s how low the river is this early,” Smith said. “We’re just not used to the river being this low this early.”
But even with the levels being abnormal for this time of year, Smith said it’s not that rare taking into account the high drought levels.
“The river levels are driven by rainfall, and since all of the areas that determine what the river will look like haven’t gotten any rain in a while, the river is low,” Smith said. “If we had received normal rainfalls in any of those areas, we would have average river levels, but we haven’t.
“That’s what’s driving this train.”
Smith said rainfall at the White River Basin in Arkansas and the lower Ohio River Valley directly affect the Mississippi River levels in Natchez and Vicksburg.
No rain in the North equals low-river levels down South, Smith said.
But the drought to the north and south could be coming to an end with a five-day forecast showing 2 to 3 inches of rainfall for those areas.
“That’s the most amount of rainfall I’ve seen on the five-day forecast in a while,” Smith said. “But we’ll need a lot more rain to get the river levels back to average.”
A National Weather Service extended stream flow prediction for river levels at Natchez estimate the levels rising to 12 feet for the next two weeks, before dropping even lower to an estimated 10 feet near the end of the month.
“The river has been significantly lower than this at times, but it’s definitely not normal for this time of year,” meteorologist Alan Gerard said. “If we continue to have dry weather, especially up in the Ohio Valley, then the river levels will continue to fall.”
Adams County Emergency Management Director Stan Owens referenced 1988 as the last time he recalls the river levels being this low.
“Most people around here probably remember that the most because it was probably around 2.6 feet,” Owens said. “If I remember correctly, that was in July, too, so it was also abnormal timing.”
As the river levels continue to fall, sandbars and even the bottom of the river become exposed, leaving dangerous traps, Owens said.
“People need to be very careful and not think they can just walk out and stand on those sandbars,” he said. “The river current can wash up and take it all away, including whoever is standing on it.
“Everyone just needs to be safe and careful around those exposed areas.”