Geographic information system (GIS) mapping is slowly becoming commonplace in irrigation districts as the need for more accurate and organized data becomes increasingly important. The Irrigation Training and Research Center (ITRC) at California Polytechnic State University, San Luis Obispo commonly uses GIS as a tool in technical assistance packages for irrigation districts. One of the challenges in developing a strategic irrigation district modernization plan is to organize spatial data in such a way that various options can be easily understood. ITRC uses a combination of commercially available software with web-downloadable maps and photographs to organize and present the spatial information. An example of information organization for a Rapid Appraisal Process (RAP) of Tulare Irrigation (TID) district is given, showing how the district boundary, major portions of TID’s open channel distribution system, field boundaries, biannual groundwater elevation contours, major water bodies, streams, rivers, and wetland areas are overlaid on two basemaps, one with aerial photographs and the other with USGS topographic maps (1:24,000 and 1:100,000), using ArcView® GIS and the 3D Analyst extension.
Available at: http://works.bepress.com/djhowes/2/