I highly recommend this FAO report by Chris Perry et al.
Abstract: Unsustainable water use (over-drafted aquifers, seasonally dry rivers, disappearing lakes and wetlands) is a problem across the world. This is especially true in the NENA region, which includes many of the most water-short countries in the world. This review indicates that there are rather few examples of carefully documented impacts of hi-tech irrigation, while there are many examples of projects and programs that assume that water will be saved and productivity increased. The conclusion of this report is that restoring a balance between sustainable supply and consumption of water requires first physical control of the water resource by government or other agencies responsible for sustainable use, followed by interventions to reduce allocations. Within the allocated and controlled quotas, hi-tech irrigation will evolve and spread to the extent that it makes sense for the farmer who wishes to take advantage of the various benefits of hi-tech irrigation.