Big Sandy Creek Watershed N-21, also known as Higbee, is a local government-owned structure located in Matheson, Colorado. This earth dam, completed in 1959 by USDA NRCS, stands at a height of 26 feet with a hydraulic height of 26 feet and a structural height of 32 feet. It serves the primary purpose of flood risk reduction along the Big Sandy Creek-TR, with a storage capacity of 368 acre-feet and a drainage area of 2 square miles.

This low hazard potential dam has a satisfactory condition assessment as of October 2020, with a moderate risk rating. It features an uncontrolled spillway with a width of 152 feet and is equipped with Needle outlet gates. The structure has undergone regular inspections with a frequency of 3 years, ensuring its continued functionality and safety for the surrounding community. With state regulation, permitting, inspection, and enforcement in place, Big Sandy Creek Watershed N-21 plays a crucial role in managing water resources and mitigating flood risks in the area.