US Army Corps of Engineers
Louisville District

Rough River Lake, Ky. Dam Rehabilitation



New!

A public meeting will be held March 5 from 5-8 p.m. at the Rough River State Resort Park Lodge

News Release Feb. 13, 2018

PROJECT FACTS 

Background: The dam site is located on Rough River, 89.3 miles east of the confluence with the Green River. Repairs are necessary to ensure the dam continues to function as it was designed for another 50-plus years. Through investigations, analyses and enhanced monitoring the Corps identified compelling evidence to warrant remedial construction. The specific concern with Rough River Dam is the karst features of specific geologic formations that lie beneath the dam. There has been no surface distress observed at the dam related with these features; however, these formations have been identified to have the potential to weaken the dam embankment. Enhanced monitoring throughout the study has indicated that adverse seepage flow may be developing within these features following the 2011 record pool. It is imperative to address these potential concerns before they worsen over time.

 Previous Construction: The planned two-phased construction project will rehabilitate the foundation to eliminate seepage concerns. The first phase of construction was split into two contracts which have now been completed.  The Phase 1A contract added rock-fill on the upstream slope of the dam and relocated KY Hwy 79. This was done to allow the Phase 1B contract to utilize the existing KY Hwy 79 as a work platform for construction.  The Phase 1B contract included the installation of over 300 grout holes as deep as 250 feet to fill void space in the rock.  This temporarily reduces the concerns related to weakening of the dam until the Phase 2 project can be installed.  Dam Safety personnel continue to closely monitor instrumentation to evaluate the condition of the dam.

Phase 2 Project: The Phase 2 project was scheduled to be advertised in December of 2017.  The design included the installation of a cutoff wall around the existing discharge conduit with drilling and grouting from inside the conduit.  As part of the project review process, additional concerns were raised with the condition of the current conduit, the long-term effectiveness of the proposed design, and unknown long-term effects on the remedial construction would have.  The Project Delivery Team (PDT) determined that the most effective way to ensure that a complete and safe project was completed was to postpone the pending advertisement and re-evaluate design alternatives. The PDT is currently in the process of evaluating potential design alternatives which range from increasing the structural capacity of the existing conduit to installing a new conduit and outlet works.  These designs will be thoroughly evaluated for constructability, effectiveness, and cost to select a new preferred design.

The Public Meeting held in April of 2017 discussed the potential for an early drawdown of summer pool in 2019.  Due to the re-evaluation of the design, this early drawdown has been canceled.  The lake will continue to operate under its current procedures, and there are currently no plans to change the lake operations. As the PDT continues through the design process, effects on lake levels will be taken into consideration and any potential future impacts will made public once known. Dam Safety personnel continue to monitor project instrumentation for signs of potential distress. Public safety is the Corps’ primary concern, and if instrumentation indicates a cause for concern then the pool levels could be adjusted to reduce risk. Corps personnel will continue to communicate progress on the project through regular updates and Public Meetings.

 

 

Rough River Dam Safety Fact Sheet