Hiwassee Dam Reservoir Report

Reservoir Report

North Carolina

Nearby: Grand Vista Dam Persimmon Creek

Last Updated: December 13, 2025

Hiwassee Dam, located on the Hiwassee River in North Carolina, is a concrete gravity dam with a height of 248 feet and a hydraulic height of 254 feet.

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Summary

Completed in 1940 by the Tennessee Valley Authority (TVA), the dam serves multiple purposes including flood risk reduction, hydroelectric power generation, navigation, and recreation. With a normal storage capacity of 398,583 acre-feet and a maximum storage capacity of 471,954 acre-feet, Hiwassee Dam plays a crucial role in managing water resources in the region.

The dam has undergone several modifications over the years to enhance its structural integrity, including seismic and structural upgrades in the early 1990s and ongoing maintenance in the following decades. Despite being classified as having a high hazard potential, the dam is regularly inspected by TVA to ensure its safety and reliability. Hiwassee Dam's controlled spillway, Tainter radial outlet gates, and proximity to the Savannah District of the US Army Corps of Engineers highlight its importance in water resource management and flood control efforts in the area.

With a very high risk assessment rating, Hiwassee Dam remains a critical infrastructure for water resource and climate enthusiasts to monitor and study. The dam's location on the Hiwassee River, its significant storage capacity, and its multi-purpose design make it a key component in the region's water management system. As climate change continues to impact water resources, understanding and maintaining structures like Hiwassee Dam will be essential in ensuring the safety and sustainability of water supplies for the surrounding communities.

Years Modified	1992 - Seismic, 1992 - Structural, 1993 - Structural, 1994 - Structural, 1996 - Structural, 2002 - Structural, 2004 - Structural
Year Completed	1940
Dam Length	1376
Dam Height	248
River Or Stream	HIWASSEE RIVER
Primary Dam Type	Concrete
Surface Area	5870
Hydraulic Height	254
Drainage Area	968
Nid Storage	471954
Structural Height	307
Outlet Gates	Tainter (radial)
Hazard Potential	High
Foundations	Rock
Nid Height	307

Explore Interactive Map

HIWASSEE DAM

Reservoir Report • Water Levels • Weather Forecast

December 13, 2025

Years_Modified	1992 - Seismic, 1992 - Structural, 1993 - Structural, 1994 - Structural, 1996 - Structural, 2002 - Structural, 2004 - Structural
Year_Completed	1940
Dam_Length	1376
Dam_Height	248
River_Or_Stream	HIWASSEE RIVER
Primary_Dam_Type	Concrete
Surface_Area	5870
Hydraulic_Height	254
Drainage_Area	968
Nid_Storage	471954
Structural_Height	307
Outlet_Gates	Tainter (radial)
Hazard_Potential	High
Foundations	Rock
Nid_Height	307

Seasonal Comparison

Weather Forecast

Nearby Streamflow Levels

Valley River At Tomotla 149.0cfs	149cfs
Tellico River At Tellico Plains 120.0cfs	120cfs
Ocoee River At Copperhill 269.0cfs	269cfs
Cheoah River Nr Bearpen Gap Nr Tapoco 132.0cfs	132cfs
Toccoa River Near Dial 225.0cfs	225cfs
Nottely River Near Blairsville 67.8cfs	68cfs

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.