Ground water

Aquifers in the Ipswich River basin mostly consist of relatively fine-grained glacial-outwash deposits that include some coarser-grained ice-contact deposits. In addition to these stratified-drift deposits, bedrock yields small but reliable amounts of water almost everywhere in the basin.

The stratified-drift deposits are generally less than 50 ft thick and underlie about 30 percent of the basin. Many are covered by organic swamp deposits. Most of the favorable areas for ground-water development are along the course of the Ipswich River or in nearby wetlands, especially in Wilmington, Peabody, Middleton, Wenham, and Hamilton. However, surface-water use during low-flow periods reduces the amount of water available to wells that are completed in stratified deposits near the river.