The high population density and the economic activities of the Mediterranean Countries have increased pressure on water resources, causing contamination of groundwater and surface water resources and salinization of coastal aquifers due to their overuse. Therefore, protecting water resources, developing high-performing supply systems and providing decision makers with integrated management tools for improving efficiency of water use and for preserving ecosystems have be identified as priority issues. In areas where water scarcity conditions occur, on-demand large scale irrigation systems can play an important role in the distribution of a scarce resource, allowing for a sound water resource management by avoiding the uncontrolled withdrawals by farmers from the source (groundwater, rivers, etc). A number of preliminary conditions have to be guaranteed for a sound water distribution. An adequate water tariff based on the volume effectively withdrawn by farmers, preferably with increasing rates for increasing water volumes, is important as a true deterrent for water surpluses. The delivery devices (hydrants) have to be equipped with flow meter, flow regulator, pressure control and gate valve, and also the use of appropriate new technologies should be taken into account.