Frd No 66, also known as the Upper Black Vermillion WS Dam 66, is a local government-owned structure located in Lillis, Kansas. Built in 1973 by the USDA NRCS, this earth dam stands at a height of 21 feet and serves primarily for flood risk reduction along the Irish Creek-TR river or stream. With a maximum storage capacity of 115 acre-feet and a normal storage of 25 acre-feet, it covers a surface area of 5.1 acres and has a drainage area of 0.26 square miles.

Although Frd No 66 has a low hazard potential and is not currently regulated by the state, it plays a crucial role in mitigating flood risks in the region. The dam features an uncontrolled spillway with a width of 40 feet and no outlet gates. While its condition assessment is not rated and the last inspection date dates back to 2010, the risk assessment deems it moderate with a DSAC assigned date yet to be determined. Despite its minimal risk, the dam's emergency action plan status, inundation maps preparedness, and risk management measures remain undisclosed.

Water resource and climate enthusiasts interested in the construction and functionality of Frd No 66 will find valuable insights in its design and purpose. As a key flood risk reduction infrastructure in Marshall County, Kansas, this earth dam showcases the collaborative efforts of local government and USDA NRCS. With its strategic location and hydraulic specifications, Frd No 66 stands as a testament to effective water resource management in the region.