Hartwell Dam water-control and power-generation structure
|Location||Anderson County, South Carolina / Hart County, Georgia, USA|
|Construction cost||USD $89,240,000|
|Operator(s)||U.S. Army Corps of Engineers|
|Dam and spillways|
|Height||204 feet (62 m)|
|Length||3 miles (4,828 m)|
|Surface area||55,900 acres (22,600 ha)|
|Installed capacity||421 MW|
|Annual generation||468,000,000 KWh annually|
Hartwell Dam is concrete and embankment dam located on the Savannah River at the border of South Carolina and Georgia, creating Lake Hartwell. The dam was built by the U.S. Army Corps of Engineers between 1955 and 1962 for the purposes of flood control, hydropower and navigation. The concrete and earthen structure spans 15,840 feet (4,828 m). The concrete section is 1,900 feet (579 m) long and rises 204 feet (62 m) above the riverbed at its apex. The Hartwell Dam currently produces 468 million KWh of electricity annually, has prevented over $40 million in flood damage since completion and also provides recreation, water quality, water supply, along with fish and wildlife management.
In 1890, Lieutenant Oberlin M. Carter of the U.S. Army Corps of Engineers (USACE) Savannah Office issued a survey report that recommended the construction of dams on the Savannah River in order to prevent flooding in Augusta, Georgia. His report was overlooked until the 1927 Rivers and Harbors Act allowed the USACE to investigate development of the Savannah River for the purpose of hydroelectricity, navigation, flood control and irrigation. In 1933, the USACE completed the report for the entire Savannah River Basin that recommended against government flood control development of the basin but did propose two hydropower dams in the upper Savannah Basin, the Hartwell and Clark Hill dams.
The Flood Control Act of 1950 authorized the Hartwell Dam and Reservoir as a development project of the Savannah River Basin. Construction on the Hartwell Dam began in 1955 and the plan called for a 3-mile long structure containing four hydroelectricity generators along with a combined 264,000 kW·h capacity. Predicting future demand requirements, the ability to install a fifth generator in the future was provided. 1,900 ft of the dam's length consists of a concrete-gravity dam, the rest compacted earth. A year before completion, in February 1961, the dam began to inundate the Savannah River. In March 1962, the reservoir was complete behind the dam and the four original hydro-power generators went online in April. The original cost of the dam was $68.4 million USD but when completed was just over $89.2 million USD. In 1983, the fifth hydroelectricity generator was installed on the dam, raising the electricity generation capacity to 344,000 kW·h.
Hydro-power plant rehabilitation
By 1997, the four original hydro-electricity generators had exceeded their 30 year life expectancy by seven years and underwent a rehabilitation. Phase 1 began in 1997 and consisted of generator rewinding/turbine refurbishment, replacing and upgrading circuit breakers, and replacing and upgrading the transformers. Phase II consisted of replacing all of the switch-yard breakers and bus-work and updating the powerhouse and Clemson Pumping Station. Upon completion of the rehabilitation, the hydroelectricity generation capacity was increased to 422,000 kW·h, a 22.7% increase.
2007-2009 drought and controversy
In June 2007, drought triggered Level 1 conditions, resulting in reduced flows of 4200 feet sec (118 m² sec). 2 months later in August, Level 2 was triggered, resulting in a 4000 feet sec (113 m² sec) release. After receiving federal and state agency authorization, the flow was again reduced to 3600 feet sec (113 m² sec) in October 2007. In August 2008, to maintain mid-term hydroelectricity output and reservoir levels, releases below 3600 feet sec (a goal of 3100 feet sec (113 m² sec)) were explored and temporarily implemented. The flows were increased back to 3600 feet sec in February 2009 to prevent environmental damage. In October 2009, the Savannah River Basin transitioned out of drought and normal flows should soon resume.
The 2007-2009 drought raised controversy over the Southeastern Power Association's (SEPA) role of controlling the Hartwell Dam. Complaints arose that the dam was releasing excess water in order to provide cheap power to communities. In addition, environmental controversy arose as to whether the releases and subsequent draining of the reservoir during a severe drought was necessary.