Julesburg #4, also known as Big Jumbo, is a privately owned irrigation dam located in Sedgwick, Colorado. Completed in 1910, this earth dam stands at a height of 33 feet and has a length of 2400 feet, providing a storage capacity of 38,600 acre-feet to support irrigation activities in the region. Situated on the South Platte River, the dam has a spillway width of 600 feet and a maximum discharge capacity of 1400 cubic feet per second, making it a crucial infrastructure for water management in the area.

Despite its importance, Julesburg #4 poses a high hazard potential due to its unsatisfactory condition as assessed during the last inspection in October 2020. The dam's Emergency Action Plan (EAP) status and risk assessment indicate a moderate risk level, prompting the need for consistent monitoring and potential risk management measures to ensure the safety of the surrounding community. With its historical significance and key role in irrigation, Julesburg #4 serves as a critical piece of water resource infrastructure in Colorado, highlighting the intersection of water management, climate resilience, and infrastructure maintenance in the face of changing environmental conditions.