Sueno, also known as South Valley, is a private irrigation structure located in Stonewall, Colorado, along the Purgatoire River. Completed in 1989, this earth dam stands at a height of 20 feet with a length of 1091 feet, providing a storage capacity of 162 acre-feet for irrigation purposes. The dam's spillway type is uncontrolled, with a width of 27 feet, and it has a low hazard potential with a satisfactory condition assessment as of June 2016.

With its primary purpose being irrigation, Sueno also serves as a Fish and Wildlife Pond in addition to supporting agricultural activities in the region. The dam's maximum discharge capability is 3200 cubic feet per second, ensuring efficient water management for the surrounding area. Despite being privately owned, the state of Colorado regulates and inspects the structure regularly to ensure its continued safety and functionality, highlighting the commitment to water resource management and climate resilience in the region.

Located in Las Animas County, Sueno plays a crucial role in water storage and distribution, contributing to the overall water security of the area. With its stone core and uncontrolled spillway, this structure showcases a blend of traditional dam construction methods with modern safety protocols. As climate change impacts water resources, structures like Sueno become essential in maintaining a sustainable balance between agricultural needs and environmental conservation along the Purgatoire River in Colorado.