Surface water

The Buzzards Bay basin has an area of about 374 mi2 in southeastern Massachusetts. The low relief of the land has resulted in numerous wetlands, and the basin contains many small lakes and ponds. Some wetlands, especially in Rochester and Wareham, are used extensively to cultivate cranberries. There are a total of 162 lakes and ponds, of which 115 have an area of 10 acres or more. Only one lake, Snipatuit Pond in Rochester (710 acres), is larger than 500 acres.

The basin is composed of drainage basins of small streams that flow between north-to-south trending hills to Rhode Island Sound and Buzzards Bay. In their lower reaches, the streams are affected by tides and bordered by tidal marshes. Streamflows in the eastern part of the basin are relatively constant throughout the year compared to other basins farther inland because of a steady discharge of groundwater to streams from the permeable deposits of sand and gravel. In contrast, the central and western part of the basin is underlain by thinner, less permeable sand and gravel deposits that discharge less groundwater to streams. Surface runoff to streams in these areas during storms is higher than in the eastern part of the basin and, therefore, streamflows are more variable.