The Columbia South Shore Wellfield is next to the Columbia River near the Portland Airport. Some of the wells are more than 400 feet deep. Big pumps can move groundwater to wherever it is needed in Portland. We use this water in cases of drought, or when nasty weather makes the turbidity high in Bull Run. High Turbidity means that the water has become cloudy from a lot of rain washing mud into the Bull Run Reservoirs.
Rain becomes groundwater by seeping into the ground and filtering slowly through rocks and soil.