in the first place. in the second and third tanks plants refine the water quality so that it can be used for field irrigation. the reuse of treated waste water is a promising solution to the problem of water scarcity which affects agriculture in particular. the advantage is twofold it enables the conservation of upstream water resources and a reduction of downstream pollution. in the village of. waste water recycling will serve to negate several plots that have been recently abandoned for lack of available water. in the high atlas precipitation average is two hundred fifty millimeters per year the berbers have adapted to these arid conditions by building kilometers of canals