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
Pequannoc Spillway site in poor repair. Like its sister structure the Pompton Dam, the Pequannoc Spillway was originally made entirely of timber. Constructed in the early 19th century the Pequannoc Spillway aided in navigation upriver along the Morris Canal during its almost 100 years of use. The structure was also part of a system to maintain water levels along portions of the Pompton River and Ramapo River which were at the time of their construction a part of the Morris Canal. The removal of the spillway was advocated against in the 1920s by C.C. Vermeule, Decommissioning Engineer for the Morris Canal and