Re-use Yazd is a project that looks at the relationship between groundwater, and the remains of an ancient irrigation system running through the desert, from the mountains and under the sprawling city of Yazd. The qanat system is 3000 years old and is adequatly in the same state as the city itself, with some parts in total and semi-ruins, and others still in use. The reapraisal of the qanat system as a tool to rethink the city, by re-introducing it as a secondary water system addresses the critical water issue in Iran, immediately felt today, by the severe depletion of groundwater levels. Four qanats were apraised during a 10 day workshop at the Univeristy of Yazd, School of Architecture. One of them has just been rewarded UNESCO heritage monument along with 10 other qanats in Iran. The proposals range from urban farming, fish farming, an agrobelt, a sub-urban agro hub, collective gardens, a neighborhood water recycling system, hamam renovations, hotels, restaurants, cafés, cultural centers, and a library.