B-21a (Labette-Hackberry) is a local government-owned earth dam in Neosho, Kansas, completed in 1999 for flood risk reduction. With a height of 18 feet and a length of 1200 feet, it provides a storage capacity of 170.96 acre-feet. The dam's spillway type is uncontrolled, with a width of 40 feet, and it is classified as having a low hazard potential.

Located in the Kansas City District, B-21a plays a crucial role in mitigating flood risks in the area. Despite its moderate risk assessment rating, the dam is not currently regulated by the state. Although it has not been inspected since November 2000, its condition is listed as "Not Rated," indicating a need for further assessment to ensure its continued effectiveness in flood risk reduction.

Water resource and climate enthusiasts will find B-21a (Labette-Hackberry) an intriguing structure due to its role in managing the drainage area of 0.45 square miles and its storage capacity of 170.96 acre-feet. While its hazard potential is considered low, ongoing maintenance and inspection will be essential to ensure the dam's continued functionality in protecting the surrounding area from potential flooding events.