Mississippi flood of 1973 western tributaries such as the Missouri and Arkansas to form a final catastrophic high in June. The flood resulted in the largest volume of water to flow down the Mississippi since the Great Mississippi Flood of 1927. Both the Bonnet Carre Spillway and the Morganza Spillway were employed. The Bonnet Carre was fully opened between April 7 and June 14 for a record 75 days. The 1973 flood was the first time the Morganza Spillway was opened: from April 19 through June 13. At Memphis, Tennessee, the Mississippi was over flood stage for 63 days, more than that of the
Pequannoc Spillway which lies on the Pompton River. The Pequannoc Spillway is an early 20th-century concrete spillway over 270 feet wide, equal in girth to the Great Falls of Paterson located along the Pompton River a quarter-mile south of the Pompton dam and associated guard bank in Pequannock Township's Aquatic Park. The dam is a run-of-the-river spillway, which traverses the width of the river and at normal water elevation allows water to spill over its face. The structure is 22 feet tall, though possesses only an 8-inch over 3 foot grade on the upstream side. An associated guard house sits near the