Bonnet Carré Spillway flood of 1937, and ten times thereafter through 2016 to lower river stages at New Orleans. The most recent opening began March 8, 2018, when river levels in New Orleans were predicted to approach the flood stage of at the Carrollton Gauge which is located just upriver from Downtown New Orleans. The floodgate inlet is offset into the Mississippi River bank, at a location that had seen natural flooding for at least two centuries. The concrete structure has been designed to reduce settling into the riverbank. The opening and closing of the spillway is done by lifting out up to
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 Like its sister structure the Pompton Dam, the Pequannoc Spillway was originally made entirely of timber.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