VICKSBURG, Miss. -- The U. S. Army Corps of Engineers (USACE) Vicksburg District used its four flood control reservoirs in the Yazoo Basin – Grenada, Enid, Sardis and Arkabutla lakes – to reduce the peak flow of rainfall runoff by approximately 90 percent during the unprecedented rainfall even throughout the region in February 2019.
During the event, the four flood control reservoirs, Grenada, Enid, Sardis and Arkabutla lakes, each held an average of nine inches of rainfall runoff, which generated an estimated 320,000 cubic feet per second of combined inflow into the reservoirs.
The four Mississippi lakes were authorized by the Flood Control Act of 1936, which provided a plan designed to address flooding that originated in the Yazoo Basin. The plan included a combination of lakes supplemented by levees and drainage works in the delta area. During significant rainfall events in the basin, USACE uses the lakes to hold back water from further contributing to flows downstream in the basin. When downstream stages are low enough to permit, additional water is released from the lakes to assure as much storage in the lakes as possible for the control of subsequent floods.
Water released by the four Mississippi lakes collects where the Tallahatchie and Yalobusha rivers unite in Greenwood, Mississippi. This confluence point is known locally as Point Leflore and is the origin of the Yazoo River.
The Vicksburg District and its Greenwood Area Office operates and maintains federally authorized flood control works within the city limits of Greenwood, Mississippi, and throughout Leflore and Carroll counties. The city of Greenwood is protected by a series of flood control works, including levees, floodwalls, drainage control structures and pump stations. When the stage on the river side at Greenwood is high, the drainage control structures are closed to prevent backflow from the river into the interior of the levee system. When the drainage control structures are closed, pump stations located in select areas along the Yazoo River and Pelucia Creek Levee Systems provide removal of interior rainfall. The city of Greenwood operates and maintains most of the area’s numerous pump stations through its public works department.
The Fort Pemberton drainage control structure, located at the intersection of Highway 82 and Highway 49 North, mitigates the flow of the Tallahatchie River and bypasses it to the Yazoo River, reducing flows through Greenwood. During high water events, the flow through the Fort Pemberton structure is increased to allow more drainage through the system. When the water is low, the flow through the Fort Pemberton structure is reduced to preserve the natural flow of the Tallahatchie and Yalobusha Rivers downstream and around Greenwood.
Four streams in northwestern Mississippi, the Coldwater, Tallahatchie, Yocona, and Yalobusha rivers, form or join with the main stream of the Yazoo River, which travels through the Yazoo Delta to enter the Mississippi River at Vicksburg, Mississippi.
The Vicksburg District uses this complex system of flood control works in the Yazoo Basin to help direct the flow of water downstream and to reduce the risk of flooding.