Sedimentation Pond Hg-4, located in Hamilton, Colorado, is a privately-owned earth dam completed in 1979. With a height of 35 feet and a hydraulic height of 46 feet, this structure plays a crucial role in flood risk reduction and other purposes. The dam has a normal storage capacity of 18 acre-feet and a maximum discharge of 654 cubic feet per second, ensuring efficient water management in the area.

Despite being categorized as having a low hazard potential, Sedimentation Pond Hg-4 is considered to have a high risk level (2) based on a risk assessment. The dam, built on Hayden Gulch-OS, is under state regulation, with the Colorado Department of Water Resources overseeing its permitting, inspection, and enforcement. Although last inspected in 1991, the structure's condition assessment is currently marked as "Not Rated," highlighting the need for updated evaluation and maintenance to ensure its continued reliability and safety.

This sedimentation pond, with a surface area of 4 acres and a drainage area of 0, serves as a vital component of the local water resource infrastructure. While its design and purpose are primarily focused on flood risk reduction, its impact on the surrounding environment and community underscores the importance of ongoing monitoring and management to address potential risks and maintain operational effectiveness.