Water Through a Stone

Abstract

An aquifer broadly refers to geologic media, such as rocks and sediments, that bears and transmits usable amounts of water. An aquifer is generally in the wells of the beholder: a city’s aquitard may be a household’s aquifer. The groundwater cycle begins with the infiltration of water into the subsurface. That which isn’t captured by plants or evaporated from the land surface percolates through the unsaturated zone and recharges the aquifer through the water table. Based on water levels (hydraulic heads) and permeability of the aquifer material, groundwater flows down gradient (down potential) towards discharge points, generally springs and seeps before the advent of water wells. Depending on the geology, an aquifer may be unconfined (have an unsaturated zone and a water table) or confined (fully saturated and under pressure such that water rises above the top of the aquifer, also called artesian). Aquifers come in many shapes and forms but are commonly made from the sands and gravels of alluvium, sandstones, limestones (especially if they are karstified, i.e., partially dissolved), and fractured rocks.

Letting the days go by, let the water hold me down. Letting the days go by, water flowing underground. Into the blue again, after the money’s gone. Once in a lifetime, water flowing underground

David Byrne, Brian Eno, Chris Frantz, Jerry Harrison, and Tina Weymouth ( 1980 )