Old River Control Structure of 1973 almost caused the control structure to fail. Integrity of the Old River Control Structure, the nearby Morganza Spillway, and other levees in the area is essential to prevent such a diversion. Jeff Masters of "Weather Underground" noted that failure of that complex "would be a serious blow to the U.S. economy." The present Old River Control Structure was completed in 1964 and expanded in 1990. The first two floodgates are the Low Sill Control Structure, which regulates routine flow in the waterway, and the Overbank Control Structure, in use only when the Mississippi exceeds its banks. A navigation
67th Indiana Infantry Regiment 10-May 22. Advance from Franklin to Alexandria March 14–26. Battle of Sabine Cross Roads April 8. Monett's Ferry, Cane River Crossing, April 23. Constructing dam at Alexandria April 30-May 10. Retreat to Morganza May 13–20. At Morganza and Baton Rouge until August. Operations in Mobile Bay against Forts Gaines and Morgan August 2–23. Siege and surrender of Fort Gaines August 3–8. Capture of Fort Morgan August 23. Duty at Morganza until December. Expedition to mouth of White River November 12–20. The regiment lost a total of 249 men during service; 1 officer and 52 enlisted men killed or mortally wounded,