Morganza Spillway Structure (ORCS), in use since 1963, where floodgates are routinely used to redirect the Mississippi's flow into the Atchafalaya River such that the volume of the two rivers is split 70%/30%, respectively, as measured at the latitude of Red River Landing. During the 1973 Mississippi flood, the ORCS was being damaged due to high flow rates, leading to the opening of the Morganza Spillway to help relieve this pressure. Subsequently, the nearby Old River Control Auxiliary Structure (ORCAS) was constructed, adding additional floodgates for use during major floods. The Morganza Spillway, about downriver from ORCS and ORCAS, is designed for
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 Like its sister structure the Pompton Dam, the Pequannoc Spillway was originally made entirely of timber.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