Lake John, located in Royalton, Vermont, is a local government-owned water supply reservoir with a primary purpose of providing water to the surrounding area. Built in 1900, the earth dam stands at 27 feet in height and has a length of 240 feet, creating a storage capacity of 12 acre-feet. The reservoir covers a surface area of 1.2 acres and is fed by the White River-TR, with a drainage area of 0.08 square miles.

Despite its historical significance, Lake John is currently assessed as being in poor condition with a significant hazard potential. The last inspection in 2017 revealed the need for improvements to ensure its safety and longevity. While the state agency responsible for regulation, inspection, and enforcement (DEC) is actively involved in overseeing the dam, there are no federal agencies involved in the ownership, funding, or management of Lake John.

For water resource and climate enthusiasts, Lake John presents both a historical landmark and a current challenge in maintaining infrastructure critical for water supply. As efforts continue to address the dam's poor condition and mitigate potential risks, the reservoir serves as a reminder of the importance of proactive management in safeguarding water resources for future generations.