The Mississippi Wants to Leave. One 1963 Concrete Gate Says No.

The Old River Control Structure in Louisiana is a concrete gate, completed by the Army Corps of Engineers in 1963, that keeps the Mississippi River from switching course to the Atchafalaya. Why does the river want to leave Baton Rouge and New Orleans, what happened to the gate in the flood of 1973, and can it keep holding? The Corps concluded in 1953 that, left alone, the Mississippi would switch to the Atchafalaya by 1990. Today the structure sends roughly 30 percent of the combined flow of the Mississippi and the Red River west and holds the rest for the main channel. 0:00 The Old River Control Structure: a gate in the farmland 0:28 The Atchafalaya and the 1953 forecast 1:47 Why delta rivers jump: the Mississippi's habit 3:15 Shreve's cut, the log jam and the shorter road to the sea 5:07 If the Mississippi left: Baton Rouge, New Orleans, salt water 7:36 The 1927 flood and the 70/30 plan 8:24 The Low Sill Structure: concrete on sand 9:40 The 1973 flood: a 50-foot hole under the gates 12:11 The Auxiliary Structure and the floods of 2011 and 2019 14:15 Will the Old River gate hold? Subscribe:    / @concreteandtide   Watch next, how New Orleans keeps its walls up against the sea after Katrina:    • After Katrina, New Orleans Built a $14.5B ...   SOURCES USGS EROS, Old River Control Structure: https://eros.usgs.gov/earthshots/old-... NASA Earth Observatory, Mississippi River switching course: https://science.nasa.gov/?p=1133896 Loyola University New Orleans, Old River Control Structure: https://lucec.loyno.edu/louisianas-ol... Louisiana Sea Grant / NOAA, Atchafalaya publication: https://repository.library.noaa.gov/v... US Army Corps of Engineers overview (Louisiana ARBRE Task Force): https://gov.louisiana.gov/assets/docs... Flood Control Act of 1954, 33 U.S.C. 702d: https://www.govinfo.gov/link/uscode/3... USGS Fact Sheet 2011-3056, Atchafalaya delta: https://pubs.usgs.gov/fs/2011/3056/pd... Atchafalaya National Heritage Area, rivers and flood control: https://www.atchafalaya.org/Rivers-Fl... Jeff Masters, Weather Underground, on Old River: https://www.wunderground.com/cat6/Ame... The Advocate, Old River and the 70/30 split, 2022: https://www.theadvocate.com/baton_rou... WAFB, Old River and the 1973 flood, 2019: https://www.wafb.com/2019/06/20/showc... USACE contract to dewater the Low Sill, 2023 (DredgeWire): https://dredgewire.com/contract-award... Eos, the 2019 high water on the Mississippi: https://eos.org/features/high-water-p... ENR, 2023 salt wedge and the emergency sill: https://enr.com/articles/57198-corps-... IMAGE CREDITS (via Wikimedia Commons) CC BY 2.0 https://creativecommons.org/licenses/... Old River Auxiliary Control Structure, 2009, US Army Corps of Engineers New Orleans District (Team New Orleans): https://commons.wikimedia.org/wiki/Fi... The Morganza Spillway as seen by NASA's EO-1 satellite, 2011, NASA/GSFC: https://commons.wikimedia.org/wiki/Fi... CC BY-SA 2.0 https://creativecommons.org/licenses/... Old River Control Structures, 2011, Tobin: https://commons.wikimedia.org/wiki/Fi... , https://commons.wikimedia.org/wiki/Fi... , https://commons.wikimedia.org/wiki/Fi... and https://commons.wikimedia.org/wiki/Fi... Public domain: US Army Corps of Engineers (New Orleans District; Old River Control Complex, 2024); NOAA / NWS Historic Collection; US Coast and Geodetic Survey; Harold N. Fisk, USACE Mississippi River Commission; EPA Documerica / US National Archives (John Messina); NASA Earth Observatory (Lauren Dauphin; Jesse Allen and Robert Simmon); NASA Ocean Color (Norman Kuring); NASA Expedition 18 (ISS). Footage: Pexels. Jabriel, Beau Runnels, Reggie A Brown, David Davidson, Chathura, Tom Fisk, Alexander Wark Feeney. Map data: Natural Earth, © OpenStreetMap contributors (ODbL); elevation: Mapzen/AWS Terrain Tiles. Music and sound: original, generated for this channel. Concrete & Tide: the great works that hold back water, explained on the map. #MississippiRiver #Atchafalaya #OldRiverControl