As our Nation's resources are developed, water will play an increasingly important role, both as a resource to be developed and as a resource to be protected. The proper development and protection of our water resources, however, will depend on adequate data on the quantity and quality of our water. Much data have already been collected by hundreds of agencies, and much more are continuously being collected. Even though a vast amount of data is being collected, the potential user faces a bewildering problem in trying to determine if the specific information he needs has been collected and where it is available. To help solve these problems of matching user needs to available data, NAWDEX the National Water Data Exchange has been established.