Thelen Dam, located in Polk, Nebraska, is a privately owned structure designed by USDA NRCS and regulated by the Nebraska Department of Natural Resources. Completed in 1969, this earth dam stands at 17 feet high and spans a length of 410 feet along the TR-Big Blue River. With a primary purpose of flood risk reduction, Thelen Dam has a normal storage capacity of 25 acre-feet and a maximum storage of 80 acre-feet, serving as a vital resource for water management in the area.

Despite its low hazard potential, Thelen Dam's condition assessment is rated as poor, indicating a need for maintenance and improvement. The last inspection in May 2019 highlighted this concern, with an inspection frequency of every 5 years. The dam's emergency action plan status, risk assessment, and management measures are currently unknown, raising questions about its preparedness for potential emergencies and the overall safety of the structure.

Water resource and climate enthusiasts interested in Thelen Dam can appreciate its role in flood risk reduction and water management along the TR-Big Blue River in Nebraska. With its historical significance dating back to 1969, this structure faces challenges in maintaining its condition and safety standards, warranting further attention and action to ensure its continued effectiveness in protecting the surrounding area from potential flooding events.