South Gray, also known as Gray Lake #2, is a privately owned earth dam located in Larimer County, Colorado. Built in 1976 for irrigation purposes, this dam stands at a height of 24 feet and stretches 2676 feet in length, with a storage capacity of 1193 acre-feet. The dam's spillway is controlled and has a width of 101 feet, ensuring efficient water release during high flow events.

Managed by the Colorado Department of Water Resources, South Gray is subject to state regulation, inspection, and enforcement to ensure its structural integrity and safety. Despite being classified as having a low hazard potential, the dam's risk assessment is rated as very high, with a risk level of 1. The condition assessment in 2017 deemed the dam to be in satisfactory condition, with regular inspections occurring every 6 years to monitor its upkeep.

Located near the Boxelder Creek-Trail River, South Gray plays a crucial role in providing water for irrigation in the surrounding Windsor area. With its strategic design and operational measures in place, this dam serves as a vital resource for sustaining agricultural activities and managing water resources in the region.