The Mill Picayune Watershed Site M-3-1 in Woodbine, Iowa, is a key water resource managed by the USDA NRCS for fire protection, stock, and small fish pond purposes. This Earth-type dam, completed in 1964, stands at 48 feet high and spans 558 feet in length, with a storage capacity of 77 acre-feet. Situated on Mill Creek, the dam serves to reduce flood risks in the region, covering a drainage area of 0.35 square miles.

Owned by the local government and regulated by the Iowa DNR, this watershed site boasts a low hazard potential and a moderate risk ranking. Despite its age, the dam's condition has not been officially assessed, but it is inspected, permitted, and enforced by state agencies. The site's location, design, and operational history make it a valuable asset for water resource and climate enthusiasts interested in sustainable water management practices and the conservation of natural habitats in the Harrison County area.