Highland #2 (South) is a privately owned earth dam located in Boulder, Colorado, with a primary purpose of irrigation. Completed in 1881, this dam stands at a height of 37 feet and has a storage capacity of 4613 acre-feet. With a surface area of 178 acres, it serves multiple purposes including fish and wildlife conservation, irrigation, and recreation.

Managed by the Colorado Department of Water Resources, Highland #2 (South) is subject to state regulation, permitting, inspection, and enforcement. Despite being classified as having a significant hazard potential, the dam's condition assessment in 2020 deemed it to be satisfactory. The spillway type is uncontrolled with a width of 50 feet, and the dam has a maximum discharge capacity of 1500 cubic feet per second.

Highland #2 (South) plays a crucial role in water resource management and irrigation in the Longmont area. As a key structure in the region, it offers opportunities for fish and wildlife conservation, recreational activities, and agricultural support. The dam's historical significance and ongoing maintenance efforts ensure that it continues to contribute to the local ecosystem while safeguarding against potential risks associated with its operation.