Luling Dam Rehabilitation Honored
Congratulations to our clients at the City of Luling, recognized with a Public Works Project of the Year award for the Luling Zedler Mill Dam Rehabilitation, Historic Restoration/Preservation category, $2 million - $5 million division. Phyllis Hillhouse with the Zedler Mill accepted the honor at the American Public Works Association, Texas Chapter Annual Conference banquet on Thursday, June 25.
Concerns about Zedler Dam were first raised in October 2008, when Ottine Dam, a similar structure six miles downstream of Zedler Mill, failed. Ottine and Zedler dams were built by the same company within a few years of each other, and shared many common features. The City of Luling asked Freese and Nichols to assess the Zedler Mill dam in 2009, and we were selected to design repairs for the dam in 2011.
Assessments were severely hampered by the lack of documentation for the dam. Data collection during design included dive inspections of the dam’s foundation along with visual observations on the condition of the dam. The dive report revealed that the sandy clay soil foundation was undermined, wooden support timbers were no longer in contact with the dam concrete, and underseepage was extensive below the dam, so the City acted quickly to address these concerns.
This project aimed to preserve environmental and historic features of a structure built in 1914 while protecting the current environment for the benefit of future generations. The project team worked closely with the Texas Historical Commission to obtain approval of proposed changes and yet maintain the historical appearance of the dam. They made sure that the project met the requirements to allow rehabilitation of the dam under a nationwide U.S. Army Corps of Engineers (USACE) permit.
The dam had originally been planned for foundation restoration by cement grouting programs. However, when the timber piles were deemed unable to provide support, a new approach was developed to use micropiles which would provide the needed stability forces. Time was added to the construction schedule to provide operable mill race gates for the City’s future use and fill unexpectedly large voids in the dam foundation, with construction complete on November 3, 2014.
Above: Victor Vasquez, Freese and Nichols; Phyllis Hillhouse, Zedler Mill; Project Manager Dustin Mortensen, Freese and Nichols; TPWA President Kristina Ramirez, City of Killeen. Below: The completed dam and mill.