If the lake level drops below 3,490 feet - termed the minimum power pool - the turbines that generate electricity have to be shut down. When the water level reaches critically low thresholds, air is sucked down like a whirlpool into the penstocks, forming explosive bubbles which can cause massive failure inside the dam.
"In the Gulf, desalination is built with enough breathing room that losing one plant doesn't immediately show up at the tap," says Rabee Rustum, professor of water and environmental engineering at Heriot-Watt University Dubai.
Fifteen years ago, he searched for fish. Now he hunts plastic bottles. The fish fled from the plastic chokehold, said Sayed, who has lived on the Giza island since arriving from Assiut, further south on the Nile, as a 14-year-old fishing apprentice. Declining fish populations, caused by plastic pollution in the river, have forced approximately 180 fishers on al-Qarsaya to pivot from traditional fishing to waste collection.
Western water law is based on the prior appropriation doctrine, which gives the first entity to make "beneficial use" of water the right to keep on using that amount, even if that means that upstream "junior" users' spigots will get shut off. By the early 1900s, a rapidly growing California was enthusiastically diverting the Colorado River, with huge irrigation districts gobbling up the senior water rights.
Over time, the water evaporated to form the smaller, brinier Owens Lake. Indigenous Paiute people call the Owens Valley Payahuunadü, 'the land of the flowing water'. Today, Owens Lake is a 'Dusty Vestige of the Old West', as NASA described a photograph of the lake taken from space.