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.
Flash flooding has been a major problem in recent days in places such as Maui, Molokai and the Big Island, where rain had been falling between 1 and 2in (2.5 and 5cm) an hour overnight, according to the Hawaii emergency management agency.
The death toll from landslides and flooding in the Gamo Zone of southern Ethiopia has risen to at least 64, with dozens more people missing, police have said. The number of people missing due to the recent flood in Gamo zone has reached 128, and according to the latest information, 64 bodies have been found.
Flash flooding is a real risk and can occur quickly, without much warning. We urge people to steer clear of floodwaters and never drive through a flooded road regardless of how safe you think it may be.
In Grazalema, Spain's wettest town, a year's-worth of rain fell in a fortnight and overloaded the karst aquifer beneath it. Water rushed into homes through floors, walls and even electricity sockets. Authorities ordered everyone to evacuate. I felt a lot of fear, said Sanchez Barea, a guesthouse owner whose home is one of hundreds still in an exclusion zone.
Showers moving into the region from the Central Coast should bring steady rain to Ventura and Los Angeles counties Thursday morning, with frosty temperatures pushing snow levels lower than normal, potentially impacting commuters along the Grapevine, according to the National Weather Service. "Steady precipitation will taper off to showers by late this afternoon and become confined to the mountains by late tonight," the weather service posted in a Thursday morning forecast.
A deep area of low pressure to the south-east of New Zealand's North Island swept into the region on Sunday, bringing heavy rain, gale-force winds and dangerous coastal swells that lashed exposed shorelines. The storm triggered power outages, forced evacuations and damaged infrastructure, with further impacts likely on Monday as the system lingers for a time, before tracking southwards later.
Your donation allows us to keep sending journalists to speak to both sides of the story. The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.
The AFP news agency, citing meteorologists, said the storm lashed Inhambane with winds of up to 215km per hour (134mph). It brought down trees and power lines, leaving more than 13,000 people without power, the national electric company said. Water supplies were also cut off in several districts of the city of Inhambane. The city is home to some 100,000 people.
More than 70,000 people, mostly women and children, have fled from Tirah, a remote region in northwestern Pakistan bordering Afghanistan, as fears grow of an imminent military offensive against the Pakistan Taliban, according to local residents and officials. Pakistan's Defence Minister Khawaja Muhammad Asif has contradicted claims made by locals and provincial authorities, insisting no military operation is occurring or planned in the Khyber Pakhtunkhwa province town.
