PHYSICAL MODEL COMPLETE: USACE Vicksburg District partners with Engineers Research and Development Center to build model for Yazoo Backwater Pump Project
Posted 6:57 PM on Friday, September 9, 2022
What comes to mind when you hear the term physical model? Do you see it as something you can touch and feel? Do you imagine something from your childhood, like a model airplane or car? Or do you consider it a miniature replica of a building or design project?
The US Army Corps of Engineers (USACE) Vicksburg District, in coordination with the US Army Engineer Research and Development Center (ERDC), recently developed a physical model of the Yazoo Backwater Pump project.
Kristen Camp, Senior Project Manager for the District of Vicksburg, said, “This model was necessary to accurately address some of the questions and challenges needed during the design and development of the plan. It can also be used after the construction of the pumping station to solve potential problems related to hydraulics and engineering. »
The 1:17.62 scale model was completed in March 2022 and includes all relevant hydraulic components needed to study the approach flow entering the pump station, including an approach channel, steel walls wing, intake bays, formed suction intakes and pump columns. The model is used to reflect the admission condition of the flow approaching the admission channel. There are many different things that could impact intake conditions, such as the amount of riprap in the water, the design of the inlet channel, the slope of the wing walls, the bay width, etc.
ERDC’s Coastal and Hydraulic Laboratory is assisting the District of Vicksburg in evaluating the hydraulic performance of pump intakes for the proposed backwater pumping plant at Yazoo. According to the standards of the Hydraulic Institute, these pumps must meet certain criteria to function properly.
Kiara Pazan, research civil engineer and project leader, explained some of the test methods used to identify existing hydraulic conditions, such as determining the severity and frequency of vortices in the intake, detecting the intensity of rotation of the flow in the suction column, and determine the uniformity of velocity in the suction column.
“We want to make sure that if there is an adverse hydraulic condition that could affect performance, we are able to identify it now,” Pazan said.
One area where testing has proven beneficial is identifying unacceptable swirls in the intake that were not anticipated. Pazan and his team will complete testing in the coming weeks and provide the data results to Vicksburg District with recommendations on how to address potential issues.
The Yazoo Backwater Area Project is located on the lower Yazoo River in the state of Mississippi. In nine of the past 11 years, the Yazoo Backwater area has experienced significant flooding. This flooding occurs primarily in the spring when the two outlets, the Steele Bayou and Little Sunflower structures, which control the 4,093 square mile drainage area, are closed due to high Mississippi River levels. The Yazoo Backwater area is protected by levees on all sides. When structures are closed, precipitation in the basin is trapped and increases until the Mississippi River levels recede enough to allow these structures to be opened again.
The District of Vicksburg designed an updated pump station for the Yazoo Backwater area to release accumulated precipitation during heavy flooding. The proposed pumping system consists of 12 vertical pumps for a total volume to be pumped of 14,000 cfs. The pumphouse would reduce flood levels on land and infrastructure in the project area. However, the pump would not operate until the floors inside the levees reached an elevation of 87 feet, at which point more than 135,000 acres of mostly forested wetlands would be flooded. Additionally, whenever the Mississippi River levels are lower than the interior levels, the pump station would be shut off and the enclosed structures opened to allow gravity discharge of flood waters.
In 2019, the Yazoo Backwater area experienced the largest flooding since 1973. Approximately 430,000 acres were inundated by floodwaters damaging homes, roads, farms, businesses, churches, water management areas wildlife, farmland and forested areas for more than six months. In addition, two deaths have been attributed to flooding. The Yazoo Backwater area caught the attention of members of Congress and interagency meetings were again held. The EPA asked the District of Vicksburg to provide edits and updated revisions to the previous report which was completed in 2008. The updated report was completed and released in December 2019, but no comments were received. received from the EPA.
In 2020, the Yazoo Backwater area again experienced major flooding flooding over 370,000 acres. On November 30, 2020, the EPA officially declared that it fully supported the project to reduce flood damage and that the proposed project was not subject to the 2008 EPA final decision veto.
Congress provided funding to initiate the design of an updated pump project in March 2021. Numerous visits to the Yazoo Backwater area were made during the summer and fall of 2021 by the office from the Assistant Secretary of the Army for Civil Works (ASA(CW)) to meet with members of Congress, senior leaders from the Mississippi Valley Division and Vicksburg District, environmental agencies, and concerned citizens. EPA Administrator Michael Regan and EPA Deputy Administrator for Water Radhika Fox also traveled to Vicksburg, Miss. (CW) saying the 2020 plan for the project Yazoo pump was banned by the 2008 final ruling.
The project was presented to the Environmental Quality Council (EQC) in early 2022, and the District of Vicksburg continues to support requests for information from the ASA Office (CW) in support of discussions interagency CEQ with EPA and FWS to determine a path forward for this project.
The Yazoo Backwater Project was authorized by the Flood Control Act of 1941 as part of the Mississippi River and Tributaries System (MR&T). MR&T protects people, infrastructure, commerce, agriculture and energy. $1.75 trillion in flood damage averted along the Mississippi River.
The Yazoo Backwater Project has four main features: the Yazoo Backwater Area Embankment, the Link Channel, associated water control structures, and the Yazoo Backwater Area Pump Station. All but the pumping station were completed in 1978. The construction of the pumping station is the last remaining piece of the puzzle.