Mississippi River Flooding- Charts

Bigger Pie Forum is making a case that the lower MS River is rising and flooding more because the US Army Corps of Engineers (Corps) is not increasing the discharge to the Gulf fast enough to keep up with faster flow downriver.  The faster flow is not due to more rain because the average rainfall in the Mississippi drainage basin has increased very little in 77 years.  But the rain and snow melt runs off faster now due to increasing development upriver.  And it flows downriver faster due to Corps projects to straighten, shorten, and channel the river.

The flow downriver splits at the Old River Control Complex (ORCC) north of Baton Rouge.  Part of it (23%) flows through the ORCC down the Atchafalaya River to discharge at Morgan City, LA.  This is the shortest, steepest, fastest route to the Gulf.  It has unused capacity.  The other 77% discharges at New Orleans.  Or tries to.  It can’t handle the faster flow.  It’s a bottleneck.  So, the flow backs up, the river rises, and it floods more.

The Corps needs permission from Congress to use the unused capacity at ORCC.  And relieve the bottleneck, lower the river, and reduce the flooding.  Congress is waiting for the Corps to ask for permission.

Meantime property owners from Clarksdale to Baton Rouge are flooding more frequently, longer, and higher.

These charts document our case.