Most homes in town supply their own water through wells.

However, about 200 Wilton homes are served by South Norwalk Electric and Water, which is owned by the Second Taxing District of the City of Norwalk. This area includes all or parts of Belden Hill Road, Old Belden Hill Road, Seir Hill Road, Old Kings Highway and some of its side streets. The district’s water comes from City Lake, Rock Lake and Popes Pond Reservoir in Wilton, and New Canaan Reservoir in New Canaan. The water undergoes treatment at a filtration plant in Wilton, where chlorine is added.

Nearly 1,000 houses and businesses are on lines owned by Aquarion Water Company (