Shimmick was selected by the USACE Fort Worth District to complete the $76 million Lewisville Dam Safety Modification Project. This project marks the final phase of improvements to the Lewisville Dam, focusing primarily on spillway improvements.
The scope includes securing spillway stability by constructing 73 post-tensioned anchors, installing an upstream geomembrane blanket in the approach channel of the spillway, overlaying the spillway apron, and replacing the existing apron slab extension with a system involving two drilled pier walls reinforced with structural steel sections and connected atop with cap beams. Instrumentation to monitor structural behavior will also be installed in the post-tensioned anchors and the apron slab drainage layer.
The Lewisville Dam originally completed in 1955, is a 67-year-old earthen dam six miles long and contains 2.5 billion tons of water. It continues to function in its role of holding in reservoir water and preventing flooding downstream. Repairs are necessary, however, to enhance the dam’s long-term viability. Maintaining the integrity of the dam is important to the safety of the half-a-million people living downstream as well as the millions if not billions of dollars invested in property and infrastructure in the area.
Although safety and quality are at the forefront of every Shimmick project, team members are well aware of the high stakes involved and hold weekly meetings with the owner. The team also includes two seasoned safety managers, a season quality control manager, and requires all personnel to complete the USACE Contractor Quality Management certification class as well as incorporate specification requirements into the work planning.
According to Project Manager Enrique Nunez, “Shimmick has the right personnel to complete the work within the specified time while meeting the stringent work requirements.”
Shimmick mobilized to the Lewisville site in August with weir anchor installation scheduled to begin in November. Additional work over the next few months will include completing haul roads, setting up the construction staging area, and establishing field office trailers. This bid-build delivery project – Shimmick’s first with the USACE Fort Worth District – is scheduled to reach substantial completion on December 22, 2025.
Nunez acknowledges it is the people and the project team that will make this project successful. The Shimmick team members assigned to the Lewisville Dam project include Enrique Nunez, Project Manager; Anon Miller, Safety Manager; Mickie Cartwright, Safety Manager; Lawrin Johnson, Quality Control Manager; Robert Vallejo, Construction Superintendent; Gilly DePoorter, Superintendent; John Rhoda, Superintendent; Marbelis Mata, Project Controls; Mike Hulett, Scheduler; and Carlos Gavidia, Field Engineer.