The Lake Conestee Dam Restoration Project ("LCDRP") came into being to address the dangerous condition of the existing dam across the main stem of the Reedy River. The current dam was built in 1892 to provide hydroelectric power for Conestee Village and Conestee Mill. Built to last only fifty years or so, the dam is well beyond its engineered life span. As a result, it has significant deficiencies that require immediate action. If the dam were to fail, there would be serious consequences downstream, including the release of 2 to 3.25 million cubic yards of sediment contaminated with hazardous substances into the Reedy River, which flows directly to Lake Greenwood, Greenwood County's only source of drinking water. A breached dam would also result in serious harm to the Conestee Nature Preserve and the loss of approximately 400 acres of riverine, lacustrine, and wetland resources in the reservoir and its upstream habitat. Finally, it would cost hundreds of millions of dollars to clean up, decimate water-based activities and tourism, and negatively impact property values all along the Reedy River system and Lake Greenwood. The LCDRP aims to prevent this tragic outcome by constructing a new dam immediately downstream of the existing dam, thereby holding the hazardous substances in place, undisturbed.
Conestee Nature Preserve is a 400-acre (160 ha) preserve along three miles of the Reedy River in Conestee, South Carolina, just 7 miles downstream of downtown Greenville, with 13 miles (20.9 km) of trails, more than 6 miles (9.7 km) of them paved and 1 mile (1.6 km) of boardwalk. The Preserve contains both hardwood and evergreen forest, extensive wetlands, and a rich diversity of reptiles, mammals, and birds. At least 223 bird species have been reported, and the National Audubon Society has designated the park as an Important Bird Area of Global Significance. In 2016 the state of South Carolina made the privately owned facility a wildlife sanctuary. It is truly a treasure. Take the time to walk the trails with your family or friends. You will not be disappointed!
Below the surface of this ecological treasure, Lake Conestee hides a terrible secret. Since the early 1800s, the area now known as Lake Conestee served as a collection point for a large portion of Greenville County's economic growth. It is estimated that the lake contains between 2.5 and 3.25 million cubic yards of sediment -- enough to fill a football stadium 1.5 or 2 times over. Unfortunately, the vast majority of the deeper sediment is contaminated with hazardous substances, including toxic metals like chromium and mercury, PCBs, polycyclic aromatic hydrocarbons (PAHs), pesticides, and others. Many of these contaminants do not break down quickly and are carcinogenic, and most are present in the deeper sediments at levels well above human health and ecological limits. Fortunately, the sediments deposited since the Clean Water Act's creation if 1972 have been much cleaner, but they cannot remove the legacy of Greenville's history.
The sediment and the hazardous substances contained in the sediment would be eroded by the flow of the river and by rainfall, and would thereby be mobilized downstream. These contaminants would move down river for years, ending up in Boyd Mill Pond and Lake Greenwood. Large storms and rain events, like those commonly experienced during the wet season and with hurricanes, will move the pollutants faster.
The impacts could be severe. The persistent nature of many of the hazardous substances means they would not readily break down. They would be present for years, negatively affecting human health and the natural ecological systems of the river and the lakes. Many become concentrated in the food chain, compounding their effects over time and potentially making fish unsafe for human consumption. Some believe the sediment also contains large amounts of nitrogen and phosphorus; if true, this could lead to algae blooms and fish kills.
Yes, but there likely would not be a huge wave of floodwaters. Rather, some of the mill buildings adjacent to the river will be flooded, and the bridge at Conestee Road over the Reedy would be in the direct path of flood waters, debris, and a large mudflow. However, the bridge is well made, modern, and anchored in the bedrock, and would likely weather the storm intact.
Estimates vary, ranging from the hundreds of millions to billions. Also, Lake Greenwood is the sole source of drinking water for the area. This type of contamination would likely require major retooling of the water treatment process serving the community, costing millions more.
Since 2012, three commissioned engineering studies and countless hours of work have pointed to the best solution: Recommended Alternative #9 - construction of a new dam ten feet (10') downstream of the existing dam, anchored into the bedrock, and built to last into the next century. Attempting to fix the existing dam or tear it out would result in mobilization and release of the contaminated sediments, a result DHEC and EPA have said is an unacceptable risk to human health and the environment. The construction phase would include safeguards to protect against contingencies during construction.
The current cost estimate for Recommended Alternative #9 is $47.5 million. This amount is hundreds of millions of dollars less than cleaning up a dam failure. Ben Franklin's aphorism “An ounce of prevention is worth a pound of cure" has never been more clearly presented.
Several things. Contact your local representatives in the General Assembly, county council members, and city officials and request support for funding and construction of the dam. Rally your friends to do the same. Attend public meetings. Keep the positive, collaborative momentum of the Lake Conestee Dam Restoration Project moving forward constructively towards construction of the new dam. These resources are available in the Information Center (click here).