Blanche Lake, located in Otter Tail, Minnesota, is a state-regulated reservoir with a gravity dam constructed in 1938 by the WPA-C. The dam stands at a height of 7 feet and has a hydraulic height of 1.5 feet, providing a maximum storage capacity of 24,500 acre-feet and a normal storage capacity of 20,400 acre-feet. The reservoir covers a surface area of 1352 acres and has a drainage area of 160 square miles, with a maximum discharge of 2569 cubic feet per second.

Despite being classified as having a low hazard potential and fair condition assessment, Blanche Lake poses a very high risk due to its location and potential impact on the surrounding area. The reservoir is equipped with a controlled spillway and has a controlled outlet structure. The last inspection conducted in August 2016 indicated that the dam was in fair condition, with an inspection frequency of every 8 years. The reservoir is primarily used for purposes other than flood control or water supply, making it a unique and valuable resource for the community.

Blanche Lake, with its picturesque location and historical significance, serves as a vital water resource for the region. Managed by the Minnesota Department of Natural Resources, the reservoir plays a crucial role in water management and conservation efforts. With its rich history and strategic location on Blanche Creek, this gravity dam stands as a testament to the ingenuity and foresight of its designers, providing both recreational opportunities and essential water supply for the surrounding area.