Charter, also known as Swan Lake, is a privately owned dam located in Warba, Minnesota, along the Swan River. Built in 1967, this gravity dam stands at a height of 8 feet and has a structural height of 10 feet, with a length of 170 feet. It serves a primary purpose of "Other" and has a storage capacity of 750 acre-feet, with a normal storage level of 250 acre-feet. The dam is regulated by the Minnesota Department of Natural Resources and undergoes regular inspections to ensure its safety and compliance with state regulations.

Despite its low hazard potential and satisfactory condition assessment, Charter has a drainage area of 113 square miles and a maximum discharge capacity of 2590 cubic feet per second. The dam does not have a spillway and is not associated with any federal agencies. The last inspection was conducted in August 2016, with a scheduled inspection frequency of 8 years. Charter plays a crucial role in managing water resources in the area and contributes to flood control and water supply management for the surrounding communities. It stands as a testament to the importance of maintaining and monitoring water infrastructure in the face of changing climate conditions.