On the edge of a nature preserve in Greenville, South Carolina, a 19th-century dam carried a modern risk, one that threatened drinking water for hundreds of thousands of people downstream.
Built in the late 1800s, the structure had long exceeded its intended lifespan while holding back an estimated 3 million cubic yards of material.
For more than a century, the Lake Conestee Dam held back the byproducts of the region’s growth. As Greenville developed through the height of the textile industry and into the modern era, waste from mills flowed downstream and settled behind the dam, slowly filling what was once open water with layers of sediment…