O'Brien #1 is a privately owned earth dam located in Yuma, Colorado, along the South Republican River. Built in 1959 for the primary purpose of flood risk reduction, this dam stands at a height of 25 feet with a hydraulic height of 18 feet and a length of 306 feet. It has a storage capacity of 115 acre-feet and a maximum discharge of 526 cubic feet per second, serving as a critical infrastructure for managing water resources in the region.

Despite being rated as having a low hazard potential, O'Brien #1 is considered to have a high risk due to its condition assessment not being rated. The dam has not undergone a condition assessment since its last inspection in 1988, indicating a potential need for further evaluation and maintenance. While it currently does not have a spillway, the dam's structure and design aim to mitigate flood risks and protect the surrounding areas from potential inundation events.

Water resource and climate enthusiasts monitoring O'Brien #1 should be aware of its importance in flood risk reduction and water management efforts in the region. With its high risk rating and outdated inspection date, there is a need for continued oversight and potential updates to ensure the dam's safety and effectiveness in protecting the community and environment from flooding events.