Bagnell Dam

The dam, which forms the popular recreational Lake of the Ozarks, provides renewable and reliable energy to the state

Construction crews have poured the final yards of concrete and are completing finishing touches on Ameren Missouri’s $53 million reliability upgrade to the historic Bagnell Dam, a major source of clean energy for the state. The project includes installation of a series of new anchors and concrete on the downstream side of the dam, which improves overall safety, efficiency and reliability of the 85-year-old structure.

“For nearly a century, the Bagnell Dam has reliably powered homes and businesses across the region,” said Warren Witt, director of hydro operations at Ameren Missouri. “These upgrades ensure the dam will continue to be a top producer of clean, renewable energy for Missouri’s communities for the next 100 years.”

The project is finishing ahead of schedule. Initial work began March 2017 and included the removal of timeworn concrete from the surface of the dam. Crews then installed 67 post-tensioned anchors, strengthening the connection to bedrock. More than 66 million pounds of new concrete was poured to further weigh down the dam. This is the first major structural update in more than 30 years and builds on Ameren’s expertise in enhancing dam safety.

“The work our engineers perform to enhance the structural integrity of the Bagnell Dam continues to be viewed as a best practice and has been implemented on dams across the globe,” said Witt. “Closer to home, we know these recent improvements help drive local economic development. For example, during the first 16 months of the project more than 220 construction jobs were created for the local trades and vendors to the Osage area, translating to an estimated $40 million impact on the area through additional spending.”

Ameren Missouri hired Missouri-based MC Industrial, a McCarthy Holdings company, as the project’s on-site general contractor. Before starting the project, the construction plan was reviewed and certified by independent engineers as well as the federal government. Throughout the project, Ameren and MC Industrial worked closely to carefully plan the construction schedule and avoid major disruptions to local residents and tourists.

“The Lake of the Ozarks is beloved by residents and tourists alike – and we wanted to be sure our project wouldn’t impede enjoyment of the lake or surrounding areas,” said Witt. “We are grateful to the Lake community and its visitors for their flexibility and patience as we complete this significant project to continue to ensure clean, reliable energy to our customers.”

Bagnell Dam houses Ameren Missouri’s Osage Energy Center. In 2017 it produced more than 624,000 megawatt-hours of energy, supplying approximately 52,000 homes with renewable energy for the entire year.

Ameren Missouri has been providing electric and gas service for more than 100 years, and the company’s electric rates are among the lowest in the nation. Ameren Missouri’s mission is to power the quality of life for its 1.2 million electric and 130,000 natural gas customers in central and eastern Missouri. The company’s service area covers 64 counties and more than 500 communities, including the greater St. Louis area. For more information, visit Ameren.com/Missouri or follow us at @AmerenMissouri or Facebook.com/AmerenMissouri.

FACT SHEET

Bagnell Dam, Lake of the Ozarks, Missouri

Background

• MC Industrial was selected by Ameren Missouri as general contractor for the Bagnell Dam Anchoring project, a $53 million investment in major structural and anchoring upgrades.
• As a significant hydropower project, the scope of work demanded expertise in heavy civil and major dam rehabilitation to ensure a safe and high-quality outcome, as well as the long-term sustainability of the Bagnell Dam to provide clean energy to the surrounding community.
• The last major structural update at Bagnell Dam was completed in the early 1980s, when 277 post-tensioned anchors were installed to hold the dam into the bedrock.

Location and Dam History

• Bagnell Dam and Osage Energy Center, Lake of the Ozarks, Missouri
• The Lake of the Ozarks stretches for more than 54,000 acres in southern Missouri.
• The Bagnell Dam, which created the lake in 1931, holds back 600 billion gallons of water from the Osage River. Bagnell is the largest privately funded dam in the U.S.
• Besides holding water back for the power plant, the dam facilitates a billion-dollar tourism industry for the state of Missouri.

Project Overview

• Project team mobilized on site in March 2017 for the 18-month project, and began construction work in April 2017 with the first of three work phases.
• Project comprised of three parts: new post-tension anchors to help hold the dam to the underlying bedrock; concrete added between the highway piers to add weight to the dam; and a new concrete overlay to replace worn and cracked concrete on the east and west sections.

Construction Features

• 17,000 cubic yards of concrete placement = 66.2 million pounds
• Added a total hold back capacity by 200 million pounds
• 67 post-tensioned anchors – each has a 2 million pound hold back capacity
• 198 foundation drains
• 500′ spillway section contains 12 flood gates that spill approx. 200,000 cfs during high water
• Utilized two hydro demolition machines / robots built specifically for this project to climb the wall and remove 3 inches of concrete off the face of the dam using 35,000 psi water over 100,000 square feet of area
• 33 anchors over the spillway that required a large temporary steel work platform
• Overlay – 9 to 12 inches of sloped concrete on the downstream side of the dam; 55,000 square feet of area 

Partners

• Engineer: Rizzo (Paul C. Rizzo Associates, Inc., PA)
• Key Subcontractors: Brayman Construction, Rampart Hydro Services 

MC Industrial, Inc., a McCarthy Holdings company, serves the specialized construction needs of the industrial market nationwide, providing turnkey services that deliver uncompromising commitment to safety and quality regardless of project size or complexity. MC Industrial has decades of proven experience in a variety of markets including power & renewables, petrochemical & refinery, heavy industrial and manufacturing. More information is available at www.mcindustrial.com 

McCarthy Building Companies, Inc. is the oldest privately held construction company in the nation – with more than 150 years spent collaborating with partners to solve complex building challenges on behalf of its clients. More information about the company is available online at www.mccarthy.com or by following the company on Facebook, Twitter, LinkedIn, Instagram and Google+.

Bagnell Dam houses Ameren Missouri’s Osage Energy Center. In 2017 it produced more than 624,000 megawatt-hours of energy, supplying approximately 52,000 homes with renewable energy for the entire year.

Ameren Missouri has been providing electric and gas service for more than 100 years, and the company’s electric rates are among the lowest in the nation. Ameren Missouri’s mission is to power the quality of life for its 1.2 million electric and 130,000 natural gas customers in central and eastern Missouri. The company’s service area covers 64 counties and more than 500 communities, including the greater St. Louis area. For more information, visit Ameren.com/Missouri or follow us at @AmerenMissouri or Facebook.com/AmerenMissouri.