St. Joe Tailings, also known as Hendrich's Mining Co., is a local government-owned structure located in Boulder, Colorado. This tailings dam was completed in 1936 and stands at a height of 42 feet, with a hydraulic height of 40 feet and a structural height of 42 feet. It has a length of 1230 feet and a storage capacity of 99 acre-feet, serving primarily as a tailings containment facility.

The dam is regulated and permitted by the Colorado Department of Water Resources, with regular inspections ensuring its satisfactory condition and low hazard potential. Despite being categorized as having a moderate risk level, appropriate risk management measures are in place to mitigate any potential issues. The spillway, with a width of 120 feet, is uncontrolled, and the dam is designed to withstand a maximum discharge of 1000 cubic feet per second.

With its location along Boulder Creek, St. Joe Tailings serves a crucial purpose in managing tailings and protecting the surrounding environment from potential hazards. Its history, design, and regulatory oversight contribute to its significance in water resource and climate conservation efforts in the region.