Water is fundamental to life. Because of this vital role, the efficient management of water resources is crucial. From the smallest communities to the world as a whole, it is becoming increasingly important to regulate land development, decrease pollution, and protect water supplies. An area's water quality and supply, flood control capabilities, soil quality, and many other environmental conditions depend on how the wetlands, rivers, watersheds, and other sources of water are managed. Agencies, hydrologists, and others researching water management collect data about geographic features that influence everyday lives. This data includes elevation, streams, main roads, dams, toxic release sites, and many others. GIS provides the tools necessary for developing solutions for water resource problems by offering a way to represent water resources data. Using GIS to integrate hydrologic water resource models and information systems provides the capability to link crucial data and decision making methods. With the integration of data comes increased hope for the future of precious water sources. The stories that follow exemplify the effort to use GIS technology to manage and protect water supplies.