The objective of this paper is to present an overview of the Source Book of Alternative Technologies for Freshwater Augmentation in Latin America and the Caribbean prepared and published by the Organization of American States (OAS) as part of a joint initiative with the United Nations Environment Programme (UNEP) and the International Environmental Technology Centre (IETC). The main objective of this project was to provide water resources planners and managers with a comprehensive inventory of technologies currently in use in Latin America and the Caribbean for augmenting and maximizing the use of existing freshwater resources. The Source Book is a reference document. It is intended to present a comprehensive overview of the alternative technologies for freshwater augmentation, water quality improvement, wastewater treatment and reuse, and water conservation most commonly used in Latin America and the Caribbean. Information on the extent of the technology's application in the region, operational and maintenance requirements, approximate costs, effectiveness of the technology, level of involvement of the community, cultural acceptability, general advantages and disadvantages of the technology, and needs for future research and development is presented for each of 22 technologies for freshwater augmentation. Each technology profile includes an extensive list of contacts who are sources of information on the technology and a bibliography. The technologies generally focus on the use of freshwater for human and animal consumption, agricultural uses, and industrial uses in arid and semi-arid areas. To gather the information necessary to develop the inventory of technologies, UNEP and OAS sponsored two workshops in 1995: one in Lima, Peru for Latin American countries and the second, for Caribbean countries, in Christ Church, Barbados. The Source Book has 275 pages and is divided into four parts: Introduction, Technology Profiles, Case Studies, and Annexes. Only Part A, the Introduction, is included here. Copies of the complete Source Book may be requested from 1889 F Street, NW, 3rd Floor, Washington, DC 20006, USA; Tel: (202) 458 3556; Fax: (202) 458-3560. Email: iwrn@oas.org or can be located at http.//www.oas.org/ EN/PROG/srcecont.htm on the Internet.