Mansfield Hollow Lake and its tributary rivers are located in the Willimantic Public Drinking Water Supply Watershed area.  Further down the Natchaug River, the Willimantic Water Works draws off water to supply drinking water to 22,000 people in Willimantic and parts of Mansfield.  Many people may wonder - if the water of Mansfield Hollow Lake is clean enough to drink, then why they can’t swim in it?  Click here for a Connecticut Department of Public Health, Drinking Water Division, Source Water Protection Law fact sheet.