A hand pump provides groundwater for drinking at Big Hill Springs Provincial Park, near Cochrane. A windmill pumps groundwater for cattle southeast of Calgary. larger image [JPEG, 233.9 kb, 1075 X 790, notice]

Rain and snowmelt infiltrate the ground. Soil and rock act as giant sponges full of tiny pores and cracks that are usually less than millimetres in size. Below the water table, these holes are full of water. This is groundwater. Groundwater slowly travels through connected pores and cracks, just centimetres to hundreds of metres per year. Any rock or sediment that yields useful amounts of water is an aquifer. The volume of groundwater below us dwarfs the volume of water stored in glaciers, lakes, wetlands, and rivers.

Groundwater and surface water are one connected water system. Water wells intercept groundwater that may be on its way to springs that feed streams and rivers.

In southern Alberta, oil and gas drilling has shown that groundwater is found to depths of four kilometres or more. However, most of this groundwater is very salty. Only shallow groundwater is potable or fit to drink.