Polly A. Deane, also known as Hine Reservoir or Bergen Reservoir #3, is a privately-owned dam located in Jefferson County, Colorado. Built in 1908 by the USDA NRCS, this earth dam serves primarily for irrigation purposes, with additional benefits for recreation. With a height of 20 feet and a length of 1230 feet, the dam has a storage capacity of 760 acre-feet and covers a surface area of 38 acres.

Despite its age, Polly A. Deane poses a high hazard potential due to its unsatisfactory condition as of the last inspection in April 2020. The spillway, which is uncontrolled and 25 feet wide, can handle a maximum discharge of 1150 cubic feet per second. The dam is regulated by the Colorado Division of Water Resources and undergoes regular inspections, with emergency action plans in place. Efforts to manage the moderate risk associated with the dam are ongoing.

Located on Dutch Creek-OS, Polly A. Deane plays a crucial role in water resource management in the area. With its historical significance and potential impact on the surrounding community, the dam serves as a reminder of the importance of maintaining and monitoring our water infrastructure to ensure safety and sustainability in the face of changing climate conditions.