Much, perhaps most, of the 2019 Mississippi River flood waters are from precipitation far upstream in the basins of the Ohio, Missouri, Arkansas and Upper Mississippi Rivers. You might guess flood stages would move from north to south in the Mid-to-Lower Mississippi River as the waters travel north to south to reach the Gulf of Mexico. You’d be wrong.
Table I shows 2019 flood stages moving south to north from the Baton Rouge – Knox Landing – Natchez portion of the river. The Knox Landing gauge is ¾ of a mile south of the inlet to the Low Sill Structure of the Old River Control Structure (ORCS), south of Natchez just above the Mississippi-Louisiana border. The Low Sill Structure spans the inlet which lies on the west side of the main channel.
2019 MISSISSIPPI RIVER FLOOD
MSR Gauge Date First Flood Stage Days above Flood Stage
Knox Landing December 16, 2018 164
Natchez January 4, 2019 145
Baton Rouge January 7, 2019 142
Vicksburg January 11, 2019 133
Greenville February 16, 2019 102
Memphis February, 19, 2019 47
The Mississippi has a plug just below The Old River Control Structure resulting from soil settling out in a roughly 20 mile stretch of the river. The flood waters coming down the Mississippi can’t get past those obstacles and backup — increasing river heights to Greenville.
For more details see Dr. Xu’s video (Also located in BPF article MS River in Danger of Being Captured by the Atchafalaya River)
(Video credit to Swamp Gear and Inclusive Productions.)
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