Half of Iran has not seen a drop of rain since the end of summer —  after  the summer itself brought extreme heat and exacerbated water supply issues .  Official data, which starts measuring precipitation every year starting from September 23, shows zero rain has been recorded since then in 15 out of the country's 31 provinces. The crisis now amounts to unprecedented drought and has forced the authorities to ration water. The capital Tehran has imposed rolling restrictions on water supply to "