This spring, water levels in the main reservoir supplying Rapid City dropped so low that city officials had to start water-use restrictions much earlier than usual. The low water and ongoing drought conditions forced the state to delay putting in public boat docks at the reservoir in Pennington County. While rains in July and August helped fill the reservoir back up, the shortage raised concerns about water availability for the growing region.
A recent federal study by the U.S. Geological Survey looked at six bedrock aquifers in the Black Hills area. It found that some parts of these aquifers, especially the Madison and Minnelusa, are being used faster than they can naturally refill. These problem areas cover the most populated and fast-growing towns from Box Elder through Rapid City, Summerset, and Sturgis.
James Jones, a senior project manager at the engineering firm AE2S, said the water use in these aquifers is already outpacing recharge. He warned that with more people moving in, this trend is not sustainable. This new study adds urgency to plans for a $2 billion pipeline that would bring water from the Missouri River to western South Dakota.
Talks about this pipeline have been underway for years. The idea gained momentum in 2019 after a study from the South Dakota School of Mines showed that local water supplies wouldn’t meet demand during drought or even normal years in the future. The study said a pipeline from the Missouri River is doable despite the challenges it presents.
In 2021, the Western Dakota Regional Water System was formed to push forward on the pipeline effort. They received $8 million from the American Rescue Plan Act in 2022 to fund engineering and feasibility studies. Since then, state lawmakers and the federal delegation have continued to support the project with additional funds and proposals.
The current plan calls for a 161-mile pipeline, 72 inches wide, with a significant elevation lift, to carry Missouri River water to the region. Nearly 50 communities, including Rapid City, want to join the project and could get water through the system. The group is also exploring ways to make better use of local groundwater and surface water where it’s available.
Kristin Conzet, the director of the water system group and a former legislator, says the goal is to secure clean and reliable water for the future. She says the project will take years, maybe decades, and there’s a long list of steps to complete before construction can start. The plan is somewhat like the existing Lewis & Clark Regional Water System, which brings Missouri River water to parts of eastern South Dakota, Minnesota, and Iowa.
For now, with aquifers being stretched too thin and drought threats looming, the pipeline project stands as a crucial effort to protect water supplies for western South Dakota’s growing communities.