Over a longer period of time, historic water level data demonstrate how aquifer storage has changed in response to periods of above- and below-normal precipitation in the Bannock Range (the primary source of aquifer recharge). This water level record is from Pocatello Well #28, in south Ross Park.

Above-normal precipitation during 1980-86 and slightly above-normal precipitation in 1993-97, and below-normal precipitation in 1987-92 coincided with or preceded periods of long-term aquifer storage changes. Note that for the three-year period, 1998-00, precipitation appears to be near the fifteen-year average, but aquifer storage declined to its lowest level in 30 years of record.

Photos taken of the Highway Pond gravel pit, south of Pocatello, reveal how water table fluctuations coincide with water levels in the gravel pit.