It was a gushing river that turned the ancient town of Esfahan into a cultural paragon that twice served as capital of the Persian Empire. But today, as it trickles through Iran, the Zayandeh Rud is a dried up battleground.

Thousands of Iranians flooded the barren riverbed last month to protest against the state’s management of water resources during the worst drought in decades. Social media videos showed baton-wielding security forces step in to quell the crowd, leaving some with bloodied faces, including a middle-aged woman cloaked in a black chador.