Water, so precious a commodity in a more Islamically aware age, was managed according to stringent rules, any waste of the resource banned, and the most severe economy enforced. Thus, in the Algerian Sahara various water management techniques were used to make the most effective use of the resource.
The Foggaras, a network of underground galleries, conducted water from one place to the other over very long distances so as to avoid evaporation. Although the system is still in use today, the tendency at present is for over-use and waste of water. Still in Algeria, in the Beni Abbes region, in the Sahara, south of Oran, farmers used a clepsydra (water regulator) to determine the duration of water use for every user in the area.
This clepsydra regulates with precision, and night and day, the amount going to each farmer, timed by the minute, throughout the year, and taking into account seasonal variations. Each farmer is informed of the timing of his turn, and summoned to undertake necessary action to ensure effective supply to his plot.
In Spain/Andalusia(under Muslim caliphate), the same strict management was in operation. The water conducted from one canal to the other was used more than once, the quantity supplied accurately graduated; distributing outlets were adapted to each soil variety, two hundred and twenty four of these, each with a specific name.
All disputes and violations of laws on water were dealt with by a court-whose judges were chosen by the farmers themselves, this court named The Tribunal of the Waters, which sat on Thursdays at the door of the principal mosque. Ten centuries later, the same tribunal still sits in Valencia, but at the door of the cathedral.