Pierz Lake, located in Morrison County, Minnesota, is a state-regulated body of water managed by the Minnesota Department of Natural Resources. This gravity dam was completed in 1955 and serves a primary purpose of "Other," with a storage capacity of 3,900 acre-feet. The lake covers 189 acres and has a drainage area of 4.4 square miles, with a low hazard potential and satisfactory condition assessment as of the last inspection in April 2015.

Situated near Royalton, Pierz Lake's dam stands at a height of 6 feet, with a structural height of 8 feet and a hydraulic height of 4 feet. The dam stretches 118 feet in length and holds a normal storage capacity of 3,200 acre-feet. The surrounding Platte River-TR provides a picturesque backdrop to the lake, which serves as a vital resource for both water management and recreational purposes in the region. With state oversight in place for permitting, inspection, and enforcement, Pierz Lake remains a well-maintained and crucial component of the local ecosystem.

As a significant water resource in the St. Paul District, Pierz Lake offers a serene retreat for nature enthusiasts and climate advocates alike. Its buttress core type and unlisted/unknown foundation contribute to its structural integrity, ensuring the safety of nearby residents and the surrounding environment. With a history dating back to the mid-20th century, Pierz Lake continues to play a vital role in water conservation efforts and serves as a testament to sustainable water management practices in Minnesota.