The design of water information or basic data systems must be flexible enough to provide information and data for a broad range of interests from national to local. The system must satisfy the need for information for accounting, surveillance, and areal synthesis purposes. The network is designed by identifying specific needs in terms of maps, analyses, and studies that will provide the basic knowledge for understanding each particular phase of the groundwater system. Each specific need is then analyzed with respect to whether it will provide information on accounting, surveillance, or areal synthesis. If a particular type of map, analysis, or observation can serve any of these three functions, a network of data collection or a program of studies is outlined in detail that will provide the information needed. The method of design necessitates the establishment of accuracy levels for maps, the density of data points, confidence limits, and so forth. The information system should be under the general guidance of a single agency, but much of the work and responsibility to carry out the details of the system must be shared by a number of agencies.
