confined aquifer

A confined aquifer is a layer of rock that holds and releases water, situated between impermeable rock layers. This geological formation is a key concept in hydrology, a field focused on Earth's water. Unlike unconfined aquifers, where the water table is open to the atmosphere, confined aquifers are sealed, creating natural pressure. This pressure can cause water to flow to the surface without pumping, forming an artesian well.12

While the confining layers are not readily permeable, they can contribute water over time through slow leakage. These aquifers are vital sources of fresh water, but over-extraction can lead to depleted water tables and potential issues like saltwater intrusion.13