Spectators turned out in force to watch the Severn Bore as it swept upstream into Gloucestershire this morning.
Dozens of people lined the banks of the River Severn in Minsterworth as the four-star bore arrived shortly before 8.30am, swelling water levels.
The A48 has been closed at the Highnam roundabout by police this morning as a precaution as the tidal wave brought the water perilously close to the top of the flood defence bank.
And with a five-star bore on its way tomorrow, residents are on red alert.
“We are watching and waiting,” said parish councillor Nigel Garbutt.
“Plenty of precautions have been taken already. We have a rest centre set up in case anyone is flooded out and we have taken a delivery of sandbags to help protect people’s homes.
“The height of the water level today is a concern, because it will be even higher tomorrow.
“If it goes over the flood bank by an inch or so, that won’t be too much of a problem. But if it goes four or five inches over then it could be catastrophic for the community.”
Mr Garbutt said he expected the Environment Agency to issue a severe flood risk warning for the area later on today.