Water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during
October 22–24, 2012; these wells are part of a network established by the U.S. Geological Survey
in 2006. Maps of the October 2012 water-table altitude in the unconfined aquifer and the potentiometric-
surface altitude of the confined aquifer have similar topology to those on maps of October 2006
conditions. Between October 2006 and October 2012, water-table altitude in the unconfined aquifer
rose by as much as 1.86 feet in 6 wells and declined by as much as 14.28 feet in 77 wells; average
decline was 2.9 feet. From October 2006 to October 2012, the potentiometric-surface altitude in 10
wells completed in the confined aquifer declined between 0.12 and 20.50 feet; average decline was
6.8 feet.