photo by Ben Hillyer

It may be what happens after the flood that is the biggest concern of Miss-Lou residents and officials. The flooding and current of the river may cause erosion problems for area roads like the one pictured above in north Adams County.

What effect will flood have on area?

By Vershal Hogan (Contact), | The Natchez DemocratAdam Koob (Contact) | The Natchez Democrat

Published Sunday, April 13, 2008

VIDALIA — With the Mississippi River climbing ever closer to its predicted 56.5 feet crest, it’s hard to imagine what the river banks may look like when the water is gone.

But rest assured, the after effects are coming. And the landscape may not be what we are used to here and further south.

Erosion

With rising water and faster than normal currents, large pieces of riverbank along the Mississippi River have gone to find a new home.

And while missing pieces of riverbank are not a threat to the levees, the riverbanks do serve as a buffer between the river and the levees.

So, when the river recedes, the levee board and the U.S. Corps of Engineers will do what they can to keep the banks from caving again, Fifth District Levee Board President Reynold Minsky said.

“We’ll go in there, grade off the bank and put rock on it, depending on how bad the caving is,” Minsky said.

Caving is when pieces of the riverbank break off or are undermined by the river.Erosion is where water has run down the levee and cut a channel or otherwise started to damage it.

“If there is a lot of caving, the corps might have to mat the area,” Minsky said.

Matting is a process in which the corps levels off an area and places concrete mats on it to prevent similar caving from happening in the future.

But no matter what the authorities decide to do, it won’t be for quite a while.

“That won’t be able to be done before August or September because of the river’s height,” Minsky said.

And while the river may be claiming plenty of new dirt, it is also leaving behind its fair share of gifts along the Vidalia riverfront.

Debris

Cans, driftwood, even a lifejacket and a shoe have washed up along the riverwalk, and Vidalia Street Superintendent Lee Staggs said cleanup would begin as soon as the river starts to recede.

Of course, the river will do most of the work for the city.

“Most of the driftwood will go out with the water,” Staggs said.

It is unlikely anything interesting will wash up during the high water, Staggs said.

“When the water gets really low, there are usually a few stolen vehicles found in the river, but it’s not likely anything is going to come up right now,” he said.

And while stolen vehicles might not be turning up in the river anytime soon — chemicals are.

Environmental effects

Wendy Garrison, a biology professor from the University of Mississippi, said flooding funnels all matter of pollutants into the river.

Garrison likened the flooding seen in the river to a flooded parking lot.

“Everything goes down the drain,” she said. “But it takes everything down with it.”

Garrison said when the water is unusually high, as it is now, it has the capability to bring chemicals into the water that it ordinarily doesn’t come in to contact with.

“Things like paint, grease, fuel and fertilizers can all be brought into the river when the water gets high,” she said.

And as if chemicals being introduced into the waterway were not bad enough, Garrison said developments along the riverbank only compound the problems.

Garrison said years ago, before riverfront development, when the river flooded the saturated areas acted as a natural filter as the water slowly seeped back into the river.

But the heavily paved areas that support buildings along the river hinder the soil’s ability to filter, Garrison said.

And aside from pollutants being funneled into the river, Garrison said the flood can have far reaching ramifications.

Garrison said as flooded farmland washes into the river, the fertilizers used on their soil also wash away.

Eventually when the river empties into the Gulf of Mexico the fertilizers introduce too much nitrogen into the gulf.

That nitrogen causes algae to bloom in mass in large areas of the gulf.

As the algae dies it depletes oxygen from the water.

Fish and other sea life need that same oxygen.

“That’s what causes dead zones,” she said.

While the impact from nitrogen- rich gulf waters might not be seen for months still, one more immediate impact of the flooding will be visible almost as soon as the waters recede.

County and city roads

Manager of the Adams County Road Department Clarence “Curly” Jones said as soon as the river recedes the road department will be able to assess the condition of the county’s roads.

“Right now we just can’t tell,” he said. “We really have to wait and see.”

On Friday, Jones said only Carthage Point and Thornburg Roads were underwater.

Jones said it is not uncommon for ruts to be “washed” into a road during a flood.

“It all depends on the water and the current,” he said.

And the current going over Carthage Point Road is quite swift.

Jones did say that both of the flooded roads have very strong bases and if they need repair once the water is gone it hopefully won’t be much.

Jones said any ruts that develop in the road should be easily repairable.

In the city, cleanup on Silver Street isn’t a big concern for City Engineer David Gardnery.

“It’s done that before; it’ll be intact,” he said. “It’s all fortified with rock, the road should be fine. It’s got rip rap all on the side of it.”

Roth Hill Road, despite the city closing it on Tuesday, will not be flooded with water anytime soon.

Gardner said if the river rises another foot it will spill on to the grass area, but not the actual paved road.