The Morganza Spillway has been opened to protect Baton Rouge and New Orleans from the Mississippi River potentially overflowing its carefully-carved banks in these cities. According to Tim, this does not keep New Orleans river levels from subsiding, but stabilizes the flow rate downstream from the spillway. “Operation of [the] spillway and floodway will keep [river] stage from going above 17 [feet] at [the] Carrollton [gage].”
The US Army Corps of Engineers designed the spillway to be opened “when the flow of the Mississippi at Red River Landing, Louisiana, is greater than 1,500,000 cu ft/s (42,000 m3/s) and rising.” With 125 bays, that’s 12,000 cfs per bay. As of this writing, one Morganza bay is open. More from Tim: “The spillways operate to maintain 1.5 million cfs flow at Baton Rouge and 1.25 million cfs at New Orleans. Doing the math, 0.25 M cfs flows out [of the] Bonnet Carre [spillway].”
WWLTV New Orleans reports that the spillway may be open for several weeks.
My heart is with you, Acadiana.
- Team New Orleans, USACE Flickr Photoset
- WWLTV New Orleans coverage [with video]
- In the words of Jeffrey, “CNN is mass psycho analyzing all of South Louisiana right now,” so you can check there, too.
- Also, check GeoEye and DigitalGlobe for satellite images of Atchafalaya flooding in the coming days.
- Morganza spillway coordinates: N 30.60128 W 91.41998