CARLSBAD (California) • The reservoir created by Hoover Dam, an engineering marvel that symbolised the American ascendance of the 20th century, has sunk to its lowest level ever, underscoring the gravity of the extreme drought across the US west.
Lake Mead, formed in the 1930s from the damming of the Colorado River at the Nevada-Arizona border about 50km east of Las Vegas, is the largest reservoir in the United States. It is crucial to the water supply of 25 million people, including in the cities of Los Angeles, San Diego, Phoenix, Tucson and Las Vegas.
As at 2pm on Thursday, the lake surface fell to 327m above sea level, dipping below the previous record low set on July 1, 2016. It has fallen 42.7m since 2000 - nearly the height of the Statue of Liberty from torch to base - exposing a bathtub ring of bleached-white embankments.
The drought that has brought Lake Mead low has gripped California, the Pacific North-west, the Great Basin spanning Nevada, Oregon and Utah, plus the south-western states of Arizona and New Mexico and even part of the Northern Plains.
Farmers are abandoning crops, Nevada is banning the watering of about one-third of the lawn in the Las Vegas area, and the governor of Utah is literally asking people to pray for rain.
Firefighters are facing worsening conditions this summer - after nearly 10,000 fires in California alone during the last wildfire season burned 1.7 million ha, an area nearly as large as Kuwait.
Droughts are a recurring natural hazard but made worse recently by an accumulation of extremely dry years for most of this century. Scientists say human-influenced climate change has exacerbated the situation.
The rains that deluged the west at the end of 2015 - before the previous low-water mark was set at Lake Mead - were a mere respite from what is now a 22-year drought, the driest period in 115 years of record-keeping by the US Bureau of Reclamation, which manages water resources in the western states.
In his decade of farming in North Dakota, Mr Devin Jacobson has never seen it this dry. His 1,416ha of mostly durum wheat, canola, peas and lentils have seen little rain beyond this season, beyond 5cm late last month and about 0.6cm this week.
Officials across the west are enacting emergency measures.
On Wednesday, Arizona's governor declared an emergency after two fires burned more than 58,680ha and triggered evacuations.
The Bureau of Reclamation is likely to declare Lake Mead's most extreme shortage condition for the first time ever, which would cut water supplies to Arizona, Nevada and Mexico, said spokesman Patti Aaron.
California Governor Gavin Newsom has issued a drought emergency proclamation for 41 of the state's 58 counties, empowering the state to take greater control over water resources.