As a result of the need for basic data and the lack of a current and convenient summary concerning the surface-water resources of lown, a synoptic inventory has been prepared as a part of the present State-wide program which is made possible by State and Federal cooperative action. These hydrologic data are assembled in abbreviated form for the convenient* of the public and in order that a current State report containing stream-flow records under one cover will be more readily accessible for Iowa.

This inventory is here presented in the form of a brief compilation report which summarizes results of stream-flow measurements relating to Iowa streams through out the years during which local. State and Federal agencies have cooperated in [OWa with the water resources branch of the United States Geological Survey.

The principal basic data consist of concise summaries for gaging stations in Iowa and certain relevant locations adjacent thereto for which records for five or more complete years have been collected. These summaries include a comprehen sive description and history of each station followed by a table giving in con venient form ami for general use the figures of maximum and minimum daily dis charge and yearly mean discharge and runoff for the water and calendaryears of record, lu addition, approximately 300 miscellaneous discharge measurements, which have been made within the Stato of lown, am included in an original and convenient listing. A summary of maximum discharges at LIS places is also given together with other data pertinent to flood flow in Iowa.