Happy Hollow is a privately-owned dam located in Linwood, Kansas, designed by the USDA NRCS and regulated by the Kansas Department of Agriculture. Built in 1962 for flood risk reduction, this earth dam stands at a height of 37 feet and has a storage capacity of 324.4 acre-feet, with a normal storage level of 131 acre-feet. With a low hazard potential and a moderate risk assessment rating, Happy Hollow serves as a vital structure in the Pony Creek watershed, providing protection against floods while also offering recreational opportunities.

Managed by the Natural Resources Conservation Service, Happy Hollow features an uncontrolled spillway with a width of 140 feet and a maximum discharge capacity of 1017 cubic feet per second. The dam's primary purpose of flood risk reduction is complemented by its secondary function of recreational use, attracting visitors to its 12-acre surface area. Although its condition is currently not rated, the dam undergoes regular inspections by state agencies to ensure its safety and effectiveness in managing water resources in the region.

Despite its age, Happy Hollow continues to play a crucial role in water resource management in Leavenworth County, Kansas. With a history of successful flood risk reduction and a commitment to regulatory standards, this earth dam stands as a testament to the importance of proper infrastructure in mitigating the impacts of climate change on local communities. Water resource and climate enthusiasts can admire the engineering prowess behind Happy Hollow while appreciating its role in safeguarding the environment and enhancing recreational opportunities for residents and visitors alike.