b'Snake River Plain Aquifer SystemFIGURE 4. Map showing geology of the Snake River Plain regional aquifer system 17conservation, development, use, and managementmeasurements made through 2002 show a continued of water resources in the state of Idaho.9 Thedecline to about 5,400 cubic feet per second and Comprehensive Aquifer Planning and Management3.9 million acre-feet per year. Furthermore, these Program was designed to provide IWRB and IDWRdeclines have vacillated uncharacteristically. The with the necessary information to develop plans foructuations correspond to drought years that had managing ground water and surface water resourcesless water available for surface water irrigation and into the future. The water management plans arewet years of higher ows in the Snake River, while the designed to address water supply and demand issuesoverall trend of decreasing ow from the springs is looking out 50 years into the future and investigatedue to more acres being watered from sprinklers and strategies that will lead to sustainable water suppliesless by traditional ood irrigation.12and optimum use of water resources.10To further complicate the water shortage in Despite planning eorts, water levels in the Easternsouthern Idaho, the Treasure Valley population is Snake River Plain (ESRP) have been declining sinceexpected to increase from approximately 580,200 the 1950s, leading to a host of water conicts (seepeople in 2010 to over 1.57 million people by the Figure 4 for Snake River Plain geology). Decliningyear 2065. During this timeframe, the number of aquifer levels have aected spring ows and surfacehouseholds is projected to increase from 211,600 water ows in the Snake River, particularly in thein 2010 to 638,700. To combat water shortage, Blackfoot to Milner reach of the Snake River and thesubstantial water-demand reductions are Thousand Springs region near Hagerman.11 Springpossible through conservation eorts within the discharge can be thought of as the pulse of andomestic, commercial, municipal, and industrial aquifer - changes in aquifer levels result in changes(DCMI) sectors. While future water demand and in spring ows. At the peak spring ow in 1951, theconservation projections are uncertain, the net discharge was estimated at 6,820 cubic feet perDCMI water demand could increase from 110,000 second, totaling 4.94 million acre-feet per year. Flowacre-feet/year in 2015 to between 219,000 and Water 133'