Annex #8 is a privately owned irrigation dam located in Larimer County, Colorado, near Fort Collins. Completed in 1903, this Earth dam stands at a height of 26 feet and has a length of 1960 feet, providing a storage capacity of 4385 acre-feet for irrigation purposes. Situated on the Cache la Poudre River, Annex #8 is regulated by the Colorado Department of Water Resources and is subject to regular inspections to ensure its structural integrity.

Despite being classified as having a significant hazard potential, Annex #8 received a satisfactory condition assessment during its last inspection in June 2019. The dam's Emergency Action Plan was last revised in December 2018, and it is noted to meet guidelines for risk management measures. With a moderate risk assessment rating of 3, Annex #8 remains a crucial piece of infrastructure for water resource management in the region, serving as a vital source for irrigation in the surrounding agricultural areas.

Owned and operated privately, Annex #8 plays a key role in water resource management and climate adaptation efforts in Larimer County, Colorado. With its historical significance dating back over a century, this dam continues to provide essential water storage capacity for agricultural activities, highlighting the importance of maintaining and monitoring such vital infrastructure in the face of changing climate conditions and increasing water demands.