The Mississippi River Is Trying to Change Course
The long why
410 views
Why doesn't the Mississippi River change course? In 1952 the Army predicted it would leave New Orleans by 1975. It's still here, and here's why.
A documentary about the Old River Control Structure, the Army Corps of Engineers machine that holds the Mississippi in place, and the Atchafalaya River, the shortcut the river wants to take. It's the story of how rivers change course, of the 1927 flood, of the spring of 1973 when the structure almost failed, and of the price Louisiana pays in land loss to keep New Orleans on its river.
00:00 One April evening, 1973
01:28 I · The wandering river
03:03 II · The shortcut
04:43 III · The flood
06:54 IV · The deadline
07:54 V · The machine
09:30 VI · Remember the guess?
10:43 VII · The price
12:31 VIII · Sooner or later
Sources (data and facts)
H. N. Fisk, Geological Investigation of the Atchafalaya Basin and the Problem of Mississippi River Diversion, Mississippi River Commission / Waterways Experiment Station, 1952 (§216–217, "uncontrollable", 1965–75)
H. N. Fisk, Geological Investigation of the Alluvial Valley of the Lower Mississippi River ("Ancient Courses"), USACE / MRC, 1944
US Army Corps of Engineers, New Orleans District, Old River Control (1981): distances 315 vs 142 mi, the 1954 authorization, the Low Sill (11 gates, 1,920 piles), the 1973 flood and repairs, the 22 ft limit
Walshire et al., Old River Control Low Sill Structure: Monitoring and Performance, ERDC/GSL MP-25-3 (2025)
USACE New Orleans District, Low Sill dewatering contract (2023) · saltwater sills 2023 (DVIDS) · fresh-water barges to Plaquemines Parish (2023)
NOAA National Weather Service New Orleans, Mississippi River Flood History 1543–Present (1927, 1973, 2011, 2019)
Shaw et al., Water Resources Research 57(5), 2021 (Atchafalaya flow share, 1926–1950)
USGS OFR 98-36 (delta lobes, after Frazier 1967) · Meade & Moody 2010, Hydrological Processes (sediment decline)
USGS SIM 3381, Couvillion et al. 2017 (coastal land change since 1932) · USGS 1984–2025 land-loss assessment (2026)
NASA Earthdata (refining share, "A Tale of Two Rivers") · NASA Earth Observatory (Morganza 2011, coastal Louisiana)
1927 flood: 64 Parishes, Britannica, Smithsonian, Library of Congress · Flood Control Act of 1928
Mid-Barataria Sediment Diversion: CPRA / USACE permit records, terminated July 2025
John McPhee, "Atchafalaya" (The Control of Nature, 1989), and Jeff Masters (Weather Underground, drawing on J. F. Barnett Jr., Beyond Control, 2017), for the April 1973 account (LeRoy Dugas, Raphael Kazmann)
Perry Gustin, interview with WAFB (2019): the "wing wall" radio call. The waveform on screen is illustrative.
The 3D terrain, the Old River model, the paper diagrams and the Morgan City village are illustrations, not flood models.
Map and terrain data
Elevation: USGS 3DEP via AWS Terrain Tiles (public domain)
Land cover and water: ESA WorldCover 2021, © ESA WorldCover project, CC BY 4.0
River lines, Morgan City buildings and the Old River Control layout: © OpenStreetMap contributors, ODbL
Night maps: Natural Earth (public domain)
Archive (all public domain unless marked)
1927 flood film: US Army Signal Corps, Mississippi River Flood of 1927, National Archives
The Valley of the Giant (c. 1950), US Army Corps of Engineers / Mississippi River Commission, National Archives
H. N. Fisk 1944 map ("Ancient Courses") and the 1952 report, pp. 130–131: USACE / Mississippi River Commission
NOAA Photo Library, Historic NWS Collection: Mounds Landing crevasse 1927; Greenville 27 Apr 1927; Vicksburg refugee camp 3 May 1927; dynamiting the levee at Caernarvon 1927
National Archives: flooded house 1927 (NARA 285964); refugees on a railroad bridge 1927 (NARA 285968); Melville, La. 1927 (US Army Air Corps, McCook Field); Morganza Spillway in flood, May 1973 (John Messina / EPA DOCUMERICA)
US Army Corps of Engineers: outdoor kitchen on the levee, Greenville 1927 (Memphis District); Morganza Spillway opening, 17 Apr 1973; Low Sill Control Structure drawing; repairs at Old River after 1973 (via LSU Libraries / Internet Archive); Old River Control Complex 1999 (Michael Maples); geomorphology of Old River; first water barge to Plaquemines Parish, 2023 (New Orleans District)
Old River Auxiliary Control Structure, 2009: Team New Orleans, US Army Corps of Engineers, CC BY 2.0
Library of Congress: Hoover and cabinet members plan flood relief, 1927 (National Photo Company); Scenes of the great Red River raft, 1873 (R. B. Talfor); New Orleans and the Mississippi, and the Mississippi at Baton Rouge, 2021 (Carol M. Highsmith)
Government snag-boat, Harper's Weekly, 1889 (Schell and Hogan), Missouri Historical Society
NASA Earth Observatory / USGS Landsat: Louisiana wetlands 1985 and 2024; Morganza Floodway, May 2011; Reshaping Coastal Louisiana, 2020 · USGS EROS Earthshots: Old River, 2024
NOAA National Geodetic Survey: Garyville, Louisiana, 2022
#MississippiRiver #Engineering #Documentary
The Mississippi River Is Trying to Change Course
The long why
410 views
Why doesn't the Mississippi River change course? In 1952 the Army predicted it would leave New Orleans by 1975. It's still here, and here's why.
A documentary about the Old River Control Structure, the Army Corps of Engineers machine that holds the Mississippi in place, and the Atchafalaya River, the shortcut the river wants to take. It's the story of how rivers change course, of the 1927 flood, of the spring of 1973 when the structure almost failed, and of the price Louisiana pays in land loss to keep New Orleans on its river.
00:00 One April evening, 1973
01:28 I · The wandering river
03:03 II · The shortcut
04:43 III · The flood
06:54 IV · The deadline
07:54 V · The machine
09:30 VI · Remember the guess?
10:43 VII · The price
12:31 VIII · Sooner or later
Sources (data and facts)
H. N. Fisk, Geological Investigation of the Atchafalaya Basin and the Problem of Mississippi River Diversion, Mississippi River Commission / Waterways Experiment Station, 1952 (§216–217, "uncontrollable", 1965–75)
H. N. Fisk, Geological Investigation of the Alluvial Valley of the Lower Mississippi River ("Ancient Courses"), USACE / MRC, 1944
US Army Corps of Engineers, New Orleans District, Old River Control (1981): distances 315 vs 142 mi, the 1954 authorization, the Low Sill (11 gates, 1,920 piles), the 1973 flood and repairs, the 22 ft limit
Walshire et al., Old River Control Low Sill Structure: Monitoring and Performance, ERDC/GSL MP-25-3 (2025)
USACE New Orleans District, Low Sill dewatering contract (2023) · saltwater sills 2023 (DVIDS) · fresh-water barges to Plaquemines Parish (2023)
NOAA National Weather Service New Orleans, Mississippi River Flood History 1543–Present (1927, 1973, 2011, 2019)
Shaw et al., Water Resources Research 57(5), 2021 (Atchafalaya flow share, 1926–1950)
USGS OFR 98-36 (delta lobes, after Frazier 1967) · Meade & Moody 2010, Hydrological Processes (sediment decline)
USGS SIM 3381, Couvillion et al. 2017 (coastal land change since 1932) · USGS 1984–2025 land-loss assessment (2026)
NASA Earthdata (refining share, "A Tale of Two Rivers") · NASA Earth Observatory (Morganza 2011, coastal Louisiana)
1927 flood: 64 Parishes, Britannica, Smithsonian, Library of Congress · Flood Control Act of 1928
Mid-Barataria Sediment Diversion: CPRA / USACE permit records, terminated July 2025
John McPhee, "Atchafalaya" (The Control of Nature, 1989), and Jeff Masters (Weather Underground, drawing on J. F. Barnett Jr., Beyond Control, 2017), for the April 1973 account (LeRoy Dugas, Raphael Kazmann)
Perry Gustin, interview with WAFB (2019): the "wing wall" radio call. The waveform on screen is illustrative.
The 3D terrain, the Old River model, the paper diagrams and the Morgan City village are illustrations, not flood models.
Map and terrain data
Elevation: USGS 3DEP via AWS Terrain Tiles (public domain)
Land cover and water: ESA WorldCover 2021, © ESA WorldCover project, CC BY 4.0
River lines, Morgan City buildings and the Old River Control layout: © OpenStreetMap contributors, ODbL
Night maps: Natural Earth (public domain)
Archive (all public domain unless marked)
1927 flood film: US Army Signal Corps, Mississippi River Flood of 1927, National Archives
The Valley of the Giant (c. 1950), US Army Corps of Engineers / Mississippi River Commission, National Archives
H. N. Fisk 1944 map ("Ancient Courses") and the 1952 report, pp. 130–131: USACE / Mississippi River Commission
NOAA Photo Library, Historic NWS Collection: Mounds Landing crevasse 1927; Greenville 27 Apr 1927; Vicksburg refugee camp 3 May 1927; dynamiting the levee at Caernarvon 1927
National Archives: flooded house 1927 (NARA 285964); refugees on a railroad bridge 1927 (NARA 285968); Melville, La. 1927 (US Army Air Corps, McCook Field); Morganza Spillway in flood, May 1973 (John Messina / EPA DOCUMERICA)
US Army Corps of Engineers: outdoor kitchen on the levee, Greenville 1927 (Memphis District); Morganza Spillway opening, 17 Apr 1973; Low Sill Control Structure drawing; repairs at Old River after 1973 (via LSU Libraries / Internet Archive); Old River Control Complex 1999 (Michael Maples); geomorphology of Old River; first water barge to Plaquemines Parish, 2023 (New Orleans District)
Old River Auxiliary Control Structure, 2009: Team New Orleans, US Army Corps of Engineers, CC BY 2.0
Library of Congress: Hoover and cabinet members plan flood relief, 1927 (National Photo Company); Scenes of the great Red River raft, 1873 (R. B. Talfor); New Orleans and the Mississippi, and the Mississippi at Baton Rouge, 2021 (Carol M. Highsmith)
Government snag-boat, Harper's Weekly, 1889 (Schell and Hogan), Missouri Historical Society
NASA Earth Observatory / USGS Landsat: Louisiana wetlands 1985 and 2024; Morganza Floodway, May 2011; Reshaping Coastal Louisiana, 2020 · USGS EROS Earthshots: Old River, 2024
NOAA National Geodetic Survey: Garyville, Louisiana, 2022
#MississippiRiver #Engineering #Documentary