Groundwater Notes

• water table: surface of groundwater, top of saturated zone underground
  • Groundwater flow tends to mimic shape of the land -
  • It flows away from pressure, and so usually downhill (Image)
• porosity: volume of empty space in a rock
• permeability: ability of rock to transmit fluids
• aquifer: water-bearing rock
  • water is in rock like water in a sponge - in the holes
• Pumping groundwater can change direction of groundwater flow
  • Pumped well lowers water table at the well
  • can cause contamination of wells
  • near coast, can cause saltwater to flow into wells (image)
• groundwater overdrafting (using water faster than it enters the aquifer):
  • using groundwater faster than it returns to the ground (recharges)
  • Can contaminate wells, salt-water intrusion
  • Impacting flow in surrounding rivers
  • Depletion of water resources
  • Land subsidence (images)