Matawan's water system is supplied from two different sources. April through mid-October of each year the town receives water from the Middlesex Road Water Treatment Plant, which is owned and maintained by the borough. This is a ground water facility supplied from two wells drilled into the Old Bridge Sands Aquifer.  MId-October through March the town is obligated to purchase water from New Jersey American Water. The majority of the water delivered to the Matawan system by New Jersey American comes from the Swimming River Reservoir in LIncroft.