Both terminals at Gatwick Airport are suffering a severe water outage, with passengers being given bottled water.
The toilets cannot be flushed and hand-washing facilities are not working.
Passengers posted online saying they were also unable to get coffee or fill up their bottles from water fountains.
Restaurants were also closed.
Staff at the North and South terminals were handing out bottled water to passengers.
Flights are unaffected.
In a statement on social media the airport said: "A local water supply issue is continuing to cause disruption. There is currently no water supply in either terminal.
"Our staff are on hand to support passengers and provide assistance where needed, some restaurant partners have opened to provide additional seating.
"We apologise for the inconvenience caused and are working closely with SES Water to restore the supply as quickly as possible. We will provide further updates as they become available."
SES Water, which serves the airport, said: "Due to a number of complications caused by a power outage at our Bough Beech Water Treatment Works, some customers are experiencing low water pressure or a temporary loss of supply.
"We are working to overcome those complications and return the treatment works to supply as quickly as we can.
"Gatwick Airport is being affected but we are working with them while our teams work to restore normal service as quickly as possible.
"We would like to thank customers and our partners at Gatwick Airport for their patience, and we are sorry for the inconvenience this is causing."
Residents in Horley and the wider Gatwick area also reported losing their water supply, according to local media.
(c) Sky News 2026: No working toilets or running water at Gatwick as airport suffers major outage
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