Chatuge Dam Safety Modifications

If a large volume of water flows quickly over the spillway, that water could lift the concrete slabs. Once a slab is lifted, the ground is exposed to the force of the water, which could erode the spillway all the way back until it breaches the reservoir. Breaching means a failure of the dam to hold back the water.

After the California-based Oroville Dam failure in 2018, TVA performed extensive investigations to see if Chatuge had the same potential vulnerability to its spillway. TVA has judged the spillway at Chatuge Dam exhibits some vulnerability to this potential failure mechanism and has chosen to address the issue proactively.

Additionally, the dam safety profession has moved toward incorporating greater consideration of downstream consequences within evaluations of dam safety. TVA has been integrating this approach into its dam safety program as part of its ongoing commitment for all TVA dams to conform to modern standards for public protection. This change in industry practices is one factor in TVA's efforts to increase the safety of Chatuge Dam.

We have implemented several activities to ensure ongoing safe operations, including increased monitoring of the dam, increased interactions with local emergency management agencies, and placement of emergency response resources at or near the site.

If monitoring indicates risk of further spillway damage and/or failure, the reservoir could be drawn down until repairs or safety concerns caused by worsening conditions are remediated.

We took all options into consideration, including a new dam. Due to a variety of factors, including timelines, TVA is not considering construction of a new dam at Chatuge.

Most plans being considered already integrate cofferdams to minimize the duration of construction and maintain safe working conditions within the spillway. However, discharges from the spillway remain the most effective means of preventing the dangerous condition of overtopping of the embankment dam. For this reason, cofferdams cannot be used to block flows entirely over the existing spillway during the construction of spillway repairs.

TVA has worked diligently to assess the needed time and budget to complete each of the proposed modifications to the spillway and will strive to continually keep the public informed of all efforts related to Chatuge. TVA funding for the dam safety project at Chatuge is not reliant on funding from other federal agencies or any external third parties.

TVA operates as a public power utility, meaning it's not focused on profit, but on serving the public interest and ensuring low rates. Our rates are affected by factors like fuel costs, capital investments and the need to meet growing energy demand.

TVA is still obligated to evaluate the environmental and social impacts of the proposed action under the National Environmental Policy Act. These evaluations include a study of socioeconomic impacts, which is a standard component of the NEPA reviews. This analysis will inform TVA’s final decision.

TVA has consulted with local utilities, and we don’t anticipate any repercussions for their operations. TVA will be able to maintain minimum flows to ensure water supply and aquatic health.

TVA does not currently have maps which accurately depict this contour, as the contour is below the typical water surface elevation. TVA intends to obtain data to better define the location of this contour at various locations around the reservoir during the coming year.

While temporary disruptions may be necessary, TVA will be working closely with local and state governments to maintain access to launch ramps.

Section 26a permits give permission for structures to be built in accordance with approved plans which provide the specific location, size and configuration of the structure. Any decision on how to manage potential impacts at Chatuge will require further analysis.

Any potential impacts on Parrot Feather at Chatuge Reservoir will require further analysis. TVA will perform surveys once water levels return to normal to see if additional treatment is warranted if the invasive species starts to regrow.

The safety of the public is our top priority. Due to large equipment and potential hazards, access to the crest road will not be available during construction.