Which water feature is NOT considered surface water?

An aquifer is classified as a groundwater feature rather than surface water. Surface water refers to water that is found in bodies such as creeks, lakes, and rivers, which are all located on the Earth's surface. In contrast, an aquifer is a geological formation that can store and transmit water underground, providing a significant source of fresh water but remaining beneath the surface. This distinction is crucial for understanding water resources and hydrology, as groundwater and surface water have different characteristics, behaviors, and interactions within the ecosystem.