Although Middleborough is located away from Buzzards Bay’s coastline, nearly a quarter of the town lies within the Buzzards Bay watershed.

The Weweantic River, Buzzards Bay’s largest freshwater river, begins in this area and flows through Wareham to the Bay. In addition, part of Middleborough is located within the Assawompsett Ponds watershed, which provide drinking water to the city of New Bedford. The communities of Rochester, Carver, and Freetown and Lakeville all border Middleborough.