gcnewsgazette.com

Rough River to repair dam

By Matt Lasley mlasley@civitasmedia.com

March 11, 2014

The U.S. Army Corps of Engineers (USACE) Louisville District will host a public meeting next week to discuss the upcoming dam remediation project for the Rough River Lake Dam.


The meeting will be held Tuesday, March 25 from 6 p.m. to 8 p.m. at the Rough River State Resort Lodge, located at 450 Lodge Road in Falls of Rough, in the Grayson and Breckinridge rooms.


The meeting will cover the dam safety assessments of Rough River Dam, and feature presentations on the dam remediation process by Jeff Esterle, Louisville District, geotechnical engineer, a questions and answers session, and displays with descriptions of the short- and long-term work.


According to USACE Louisville District Project Manager Dianne Stratton, in July 2012, the USACE completed a Dam Safety Medition Report, which addressed “unacceptable risk due to foundation conditions that can be found when a dam is constructed on karst geology (solutioned limestone)” and recommended “major rehabilitation to ensure the structure’s integrity and lower the project’s risk.”


The USACE conducted a routine five-year dam safety inspection in June 2013, performs a formal inspection at least annually, and heightened surveillance during elevated reservoir pools.


Based on these reports, the USACE determined that repairs are necessary to ensure the dam continues to function as it was designed for another 50-plus years.


Stratton said the specific concern with Rough River Dam is the karst features of geologic formations that lie beneath it. As of now, there has been no “surface distress” observed at the dam related to these features, but they have been determined to have the potential to weaken the dam embankment.


“While the dam is currently operating as intended, and there is no emergency or imminent threat, failure of the dam would result in catastrophic effects downstream, including potential loss of life and significant economic losses,” said Stratton.


The planned tw0-phase construction project will rehabilitate the foundation of the dam to eliminate the aforementioned concerns.


The first phase will start with the movement of State Highway 79 to the lake side of the dam to ensure traffic flow will not be interrupted and also allow heavy construction equipment to access the crest of the dam, Stratton said.


The proposed work will include filling cracks, fissures, and other openings in the bedrock that underlies the earthen dam, according to Stratton.


Whether the USACE commences with Phase II of the construction project will be determined by the conditions encountered during Phase I.


Phase II “could involve a deep cut-off wall through the embankment and into the foundation rock,” said Stratton.


The project is not anticipated to have much impact on the community.


“After the construction, the surface of the dam will be restored, and its appearance will look much as it does currently,” Stratton said. “Changes to lake operations that would impact normal public use will be minimized as much as possible.”


For more information, contact the USACE at 270-257-2061.


For lake information, visit the U.S. Army Corps of Engineers, Rough River Lake website at www.lrl.usace.army.mil/rrl or Facebook at http://www.facebook.com/#!/pages/Rough-River-Lake/194425466082.