Mark Sigety has owned land in the Harquahala Valley near Tonopah since 2003. Since then, he says several investors have reached out to buy his half-acre plot along with other parcels in western Maricopa County. … The Harquahala Groundwater Basin is one of three in rural Arizona set aside specifically to import water to the Valley once water gets scarce. It’s known as an Irrigation Non-Expansion Area, or INA. It’s a place where the state or political subdivisions that own land eligible to be irrigated can pump groundwater and transport it into areas where groundwater is regulated in Arizona, known as AMAs, or Active Management Areas. The Phoenix AMA is one of them and covers land from west of Buckeye to Superior.