Saluda Dam

Saluda Dam. It is a major earthen embankment dam located on the Saluda River in Lexington County, South Carolina. Constructed in the late 1920s to generate hydroelectric power, it impounds the expansive Lake Murray reservoir. The dam is owned and operated by the utility company South Carolina Electric & Gas and serves critical roles in regional power generation, water supply, and flood mitigation.

History

The project was conceived in the early 20th century by engineer and former University of South Carolina president William S. Currell, who envisioned harnessing the Saluda River's power. The Lexington Water Power Company, a predecessor to South Carolina Electric & Gas, spearheaded the massive undertaking to meet the growing energy demands of the Midlands region of South Carolina. Construction commenced in 1927, a period of significant industrial expansion in the American South, and required the relocation of numerous families, churches, and cemeteries from the planned reservoir basin. Upon its completion in 1930, it was celebrated as the world's largest earthen dam and created what was then the largest man-made reservoir on Earth.

Construction and design

The structure is a rolled-earth fill dam, utilizing local materials like clay and soil in its core. Its construction involved moving over 15 million cubic yards of earth, a monumental task employing a large workforce and innovative machinery for the era. The primary spillway is a concrete ogee weir, while a separate intake structure channels water to the hydroelectric power plant. The dam's foundation required extensive grouting to secure it against the underlying rock strata, a common practice in major projects like the Hoover Dam. The creation of Lake Murray dramatically altered the local topography, submerging the former confluence of the Saluda River and Little Saluda River.

Environmental impact

The formation of Lake Murray transformed the local ecosystem, creating a new lentic habitat while inundating riverine environments and extensive forestland. This significantly affected native fish populations and terrestrial wildlife corridors. Over decades, the reservoir has experienced issues with nutrient loading and algal blooms, influenced by upstream agricultural runoff and suburban development in areas like Columbia, South Carolina. The stabilized water level and temperature regime also impacted downstream river ecology on the Saluda River and its confluence with the Broad River near Congaree National Park.

Safety concerns and modifications

A major seismic risk assessment in the 1990s, prompted by studies of the New Madrid Seismic Zone, revealed the original dam was vulnerable to failure in a significant earthquake. This led to the initiation of the Saluda Dam Remediation Project, one of the largest dam safety projects in United States history. The primary solution was the construction of a massive new roller-compacted concrete buttress at the downstream toe, a technique also used at dams like Wolf Creek Dam in Kentucky. This multi-year project, completed in 2005, was overseen by the Federal Energy Regulatory Commission and involved extensive cooperation between South Carolina Electric & Gas, the U.S. Army Corps of Engineers, and state agencies.

Role in water supply and recreation

Beyond hydroelectricity, the reservoir is a vital raw water source for multiple utilities, including the City of Columbia's Canal Water Treatment Plant. The lake supports a substantial recreational economy, with popular parks like Dreher Island State Park and Lake Murray Country promoting activities such as boating and fishing. Major events like the Fourth of July celebration "Red, White and Boom" and professional fishing tournaments, including those from the Bassmaster Elite Series, are hosted on its waters. The dam's controlled releases also support downstream water quality and augment flows for the Congaree River.