Patterson #1 is a historic earth dam located in Delta, Colorado, along the picturesque Leroux Creek. Completed in 1896, this structure serves primarily for irrigation purposes and water supply. The dam stands at a height of 16 feet with a length of 1000 feet, offering a storage capacity of 84 acre-feet. Despite its age, Patterson #1 has a low hazard potential and is classified as having a fair condition assessment as of its last inspection in June 2018.

Situated in the Omaha District, Patterson #1 is privately owned and regulated by the Colorado Department of Water Resources. With state permitting, inspection, and enforcement in place, this dam contributes to the agricultural landscape of Lazear and surrounding areas. The dam features slide and uncontrolled outlet gates, with a spillway width of 10 feet. While the risk assessment indicates a high level of risk, measures for risk management and emergency preparedness are not explicitly outlined, suggesting room for improvement in these areas.

Water resource and climate enthusiasts will appreciate the historical significance and functional importance of Patterson #1 in the local water infrastructure. Its presence on Leroux Creek serves as a reminder of the enduring legacy of irrigation systems in Colorado and the ongoing need for responsible dam management to ensure water security for agricultural communities. As discussions around water conservation and sustainability continue, Patterson #1 stands as a testament to the resilience of water resource management in the region.