U.S. Senate Republican Leader Mitch McConnell (R-KY) announced Monday that the U.S. Army Corps of Engineers (USACE) has dedicated $8,750,000 to the ongoing Rough River Lake Dam remediation project in its Fiscal Year 2021 Work Plan.
According to USACE, a 2012 safety report on the existing dam called for structural improvement to lower the risk of flooding to surrounding homes and communities. This was due to the dam’s being constructed on a karstic foundation, which is landscape underlain by limestone that can be dissolved by water, leaving voids within it.
“It’s been my privilege to ensure the voices of the Rough River Lake community are heard in Washington,” said McConnell. “I was proud to secure the funding that will protect local families and businesses from the danger of severe flooding. I look forward to every opportunity to support this community as we improve our critical infrastructure.”
According to Will Ailstock, Project Manager with Army Corps of Engineers Louisville District and lead engineer on the Rough River Dam remediation project, the goal of the dam remediation is to, from a long-term standpoint, “reduce the risk of the dam and make it last another 50 years.”
While Rough River Dam’s karstic foundation was not initially an issue, it has become one in the decades since the dam’s construction.
The initial phase of the project involved filling in voids in the karstic foundation with grout, and this phase was completed in 2017. The next and current phase includes the construction of a concrete cut-off wall from the crest of the dam into its foundation to prevent any water from seeping through it and new outlet works to regulate the flow of water on the left abutment of the dam, Ailstock said.
According to Ailstock, the $8,750,000 announced by McConnell was set aside in 2017 to be distributed in the Fiscal Year 2021 budget; however, at the time it was set aside, USACE had only planned to install a new cutoff wall.
Ailstock said engineers later grew concerned over installing a cutoff wall around the dam’s existing conduit, and the decision was made to install new outlet works as well. As this is expected to significantly increase the cost of this phase of the project, USACE was required to submit a supplemental dam safety modification report to its headquarters to garner approval to add the new outlet works to its designs. This report had not yet received approval at press time.
USACE is currently working to update the designs for this phase of the dam remediation project, and the updated design is expected to be completed later this summer.
In order to award the construction contract, USACE will require additional funding for the inclusion of the new outlet works, so Ailstock could not say when construction on this phase of the dam remediation project might begin; however, engineers estimate that, after construction starts, it will take around five to seven years to complete.
Ailstock said USACE typically holds public meetings on the Rough River Dam remediation project every year to update the community on its status. While unable to hold one last year due to the COVID-19 pandemic, USACE hopes to hold one this spring either in person or virtually.