The purpose of this report is to summarize data on the use of water in the Delaware Basin Project area (fig. 2) and to list the principal data sources that are available in published form. The tables and bibliography will assist Geological Survey personnel assigned to the Delaware Basin Project in evaluating the scope and deficiencies of previous studies of the basin. Information is also given on the use of water by public supplies in the New York-New Jersey region comprising the New York City Metropolitan Area and in the remaining north-central and south-eastern parts of New Jersey. These regions may depend increasingly on water from the Delaware River basin for part of their public supplies.

The Geological Survey has the responsibility for appraising and describing the water resources of the Nation as a guide to use, development, control, and conservation of these resources. Cooperative Federal-State water-resources investigations in the Delaware Basin States have been carried on the the Geological Survey for more than 50 years. In July 1956 the Survey began the "Delaware Basin Project," a hydrologic study of the Delaware River basin in order to: 1) Determine present status and trends in water availability, quality, and use, 2) assess and improve the adequacy of the Survey's basic water data program in the basin, 3) interpret and evaluate the water-resources data in terms of past and possible future water-use and land-use practices, and 4) disseminate promptly the results of this investigation for the benefit of all interested agencies and the general public. The Geological Survey is working closely with the U.S. Corps of Engineers and other cooperating Federal and State agencies in providing water data which will contribute to the present coordinated investigation aimed at developing a plan for long-range water development in the Delaware River basin.

Estimates of quantities of water used are given for water withdrawn from streams and aquifers during calendar year 1955, as compiled or estimated from publications and manuscripts prepared between 1950 and 1956. All quantities are given in millions of gallons per day (mgd). The source of the water used, ground or surface, and the type of use to which is was put -- public supply, industrial supply, irrigation, or rural use -- is given. Use of water for hydroelectric power was not compiled for this report. Most tables in this report do not subdivide withdrawals into fresh and saline water; however, most supplies are fresh, except some of those withdrawn directly from the Delaware River downstream from Philadelphia, Pa. All quantities are expressed as an average rate for a full year and are lower, therefore, than rates resulting from the increased demand for water during the summer for air conditioning and supplemental irrigation.

The primary emphasis of this study was to get an over-all picture of water use throughout large parts of the basin. Therefore, publications relating to a dingle city or county, other than New York City, seldom were used; revisions and refinement based on such sources of information are best made by the field personnel most familiar with locally filed publications and published data.