How far downstream will the Mississippi River flood?

[HarlequinBoy]

I see a major flood is forecast along the River from at least St. Louis and up, but does anyone know how far downstream it could come back out of its banks? I know in '93 it didn't get bad south of New Madrid. My dad owns a lot of farmland that's actually behind the levee system here and a flood this late will ruin a lot of crops. We already had a pretty significant flood in March and April and the River came up about 1/4 of the way up the levee, but flooded everything behind it. The highest stages since '97 or before in some places.. I'm kind of doubting it floods down here, hopefully, but the New Madrid station is already expected to reach flood stage soon.

[Ed Mahmoud]

I don't know. I do recall hearing that in actuality the Mississippi is a tributary of the Ohio River, where they meet normally the Ohio carries somewhere near twice as much water.


So an Ohio River flood is worse than a Mississippi flood for points downstream of the confluence, but I imagine a bad enough Upper Mississippi flood would also flood downstream.

[HarlequinBoy]

You make a good point. I checked the Ohio stations and they are going to be around action stage, with a few peaking at flood stage so that's not too bad.

However, in '93 I think part of the reason the River didn't flood downstream was the enormous breaches in Missouri and Illinois relieved some of the stress and volume.

[CrazyC83]

You make a good point. I checked the Ohio stations and they are going to be around action stage, with a few peaking at flood stage so that's not too bad.

However, in '93 I think part of the reason the River didn't flood downstream was the enormous breaches in Missouri and Illinois relieved some of the stress and volume.

That seems to make sense, since the water would have spread out enough so that when it gets to the wider parts there is less floodwaters to come in.

[HarlequinBoy]

Good call on the Ohio River.

FLOODING IN IOWA ALONG THE CEDAR AND IOWA RIVERS IS BRINGING
A LOT OF MEDIA ATTENTION. RECORD FLOODING IS OCCURRING
ALONG THESE RIVERS. THE UPPER MISSISSIPPI RIVER IS
EXPERIENCING MAJOR FLOODING FROM DAVENPORT IOWA TO
JUST NORTH OF ST. LOUIS. THE MIDDLE MISSISSIPPI
RIVER IS FORECAST TO GO INTO MAJOR FLOOD.

THE OHIO RIVER IS CURRENTLY FALLING. THIS WILL HELP
TO BALANCE THE INCREASE IN FLOWS FROM THE MIDDLE
MISSISSIPPI RIVER. THE MISSISSIPPI RIVER
SIGNIFICANTLY WIDENS BELOW THE POINT WHERE
THE OHIO RIVER CONVERGES WITH THE MISSISSIPPI RIVER.
BASED ON CURRENTLY CONDITIONS... THIS SHOULD KEEP THE
LOWER MISSISSIPPI RIVER BELOW FLOOD STAGE FROM
ARKANSAS CITY TO NATCHEZ. THE RIVER CREST IS NOT EXPECTED
IN THIS AREA UNTIL THE LAST SEVERAL DAYS OF JUNE.

WE WILL NEED TO MONITOR THE AMOUNT OF RAINFALL THAT
OCCURS OVER MISSOURI AND PORTIONS OF ILLINOIS
IN THE NEXT 24 HOURS AND THE OHIO RIVER IN THE
NEXT 48 HOURS. RAINFALL IN THESE AREAS COULD
HAVE ADDITIONAL IMPACT ON THE LOWER MISSISSIPPI
RIVER.


So as long as it doesn't rain too much more up there it will be ok down here. Farmers lost quite a bit of money already this year when we had record rains in March and April.