Pool
"A pool is place where water is stored, like the ocean, ice sheets, groundwater, rivers, lakes, and snowpack." (U.S. Geological Survey, 2022)
Sources
U.S. Geological Survey (USGS). "Water Cycle Glossary Terms". USGS Water Science School. (2022). Link: https://www.usgs.gov/glossary/glossary-water-cycle-terms