This paper aims to describe the state of theart of both water harvesting (WH) andsupplemental irrigation (SI) techniques in the temperate and sub-tropical dry lands, especiallyin the countries of WANA that are characterized by a Mediterranean-type climate. In addition,three case studies of water harvesting are presented (see annex). These were selected from the case studies presented at the FAO Expert Consultation Cairo (1994). By sharing with us the success and the failure of these endeavors, the authors of the case studies illustrate many of the points that are made in the text.