The NY Times has a recent article about the water crisis in Yemen.  One problem is that a lot of agricultural lands are devoted to growing qat trees,

which have replaced other crops across much of the country, taking up a vast and growing share of water.

Further, the Times reports,

some clerics have declared the reuse of wastewater to be a violation of Islamic principles.

I’ve worked some in Jordan, and have run into this problem before, which apparently has been solved.  It seems these clerics in Yemen may not be aware of a “Fatwa of the Council of Leading Islamic Scholars in Saudi Arabia,” detailed here by the Ministry of Water in Jordan, which reads as follows:

The Council of Leading Islamic Scholars in Saudi Arabia issued a fatwa in 1978 stating that reclaimed water can be used for ablution and drinking if it is sufficiently and appropriately treated to ensure good health. The Scholars Council of the Kingdom of Saudi Arabia States:

“According to the report set by the experts in this regards, a large body of water would be pure from any impurity if such impurity is removed, if more water added to it, or if such impurity is eliminated by the passing of time, the sun, the wind or any other cause that would remove its impurity. Impure water could be purified by the modern filtering techniques that are the best and most efficient methods for purification, in which many materials will be added to remove impurities ad certified by the water treatment experts. Therefore, this Council believes that such water will be totally pure and it may be used for ritual purification and drinking as long as there are no negative consequences on health. If drinking is to be avoided, it is merely for reasons of public health and safety, not due to any ramifications of Islamic Law. The Council recommended avoiding using this treated water for drinking purposes to avoid health problems and also in consideration of the negative public sentiment about this water “.