A river in Hereford has reached its highest level in at least 200 years in the wake of Storm Dennis lashing the area with torrential rain.
The River Wye reached 20ft (6.11 metres) – its highest since records began – on Monday, with residents in Hereford saying they had never seen anything like it.
Over the weekend, the River Taff in Pontypridd reached its highest level in more than 40 years and the River Usk reached the highest level since 1979.
The River Trent, which had prompted a severe flood warning for Burton-on-Trent, also peaked at a record level of just below 4 metres on Tuesday.
Hundreds of properties have been flooded and at-risk areas evacuated across England and Wales after the downpours brought to the UK by Storm Dennis.
Flood-hit communities are braced for further heavy rain as river levels continue to threaten to breach barriers.
Kate Marks of the Environment Agency (EA) said that even though Storm Dennis had passed, "we'll be feeling the impacts for a few more days”.
"There's a lot more water in the river systems. In particular we are worried about the Rivers Severn, Teme and Wye," Dr Marks said.
Both the Rivers Wye and Severn will remain especially high into the weekend.
West Mercia Police said an estimated 384 properties had been "significantly impacted by the floods" across Worcestershire, Herefordshire and Shropshire.
Residents in the Shropshire towns of Ironbridge and Bridgnorth were urged to evacuate their properties, while residents in Bewdley near Kidderminster were warned flood barriers at Beales Corner might not be able to withstand the rising water levels.
Deputy Chief Constable Julian Moss said: "Water levels have been unprecedented in many places and the impact of such high-levels of flooding has been substantial across all the agencies, but more significantly to members of the public affected in any way.”
The EA said 599 properties had been flooded across England as of Tuesday afternoon. Some 800 homes in Wales had been directly affected by flooding, first minister Mark Drakeford told the BBC.
More than 6km of temporary flood barriers have been erected across the country and flood defences have protected nearly 25,000 properties from the impacts of the storm, the EA said.
But record-breaking river levels and continued rainfall means further flooding is possible across much of the country, said EA executive director of flood and coastal risk management John Curtin.
"We expect further disruptive weather into tomorrow and Thursday, bringing a significant flood risk to the West Midlands, and there are flood warnings in place across much of England," he said.
The Met Office said rain would start to build up in the west from mid-morning on Wednesday.
Over the next two days there could be up to 100 millimetres of rain in north Wales and 50-60mm in south Wales.
The rain will then move north, with Cumbria and Yorkshire likely to be most affected.
The Met Office has issued yellow weather warnings for persistent rain in Wales and North West England for Wednesday and Thursday, and the north of England on Friday into Saturday.
EA manager for Herefordshire and Worcestershire Dave Throup said the level of flooding had left affected parts in "uncharted territory”.
Six severe flood warnings remained in place on Wednesday morning: for the River Wye and the River Lugg at Hampton Bishop; for the River Severn at New Street and Waterside, Upton on Severn; and for the River Severn at Ironbridge and Uckinghall.
In Wales, two severe warnings in place on the River Wye at Monmouth were downgraded by Natural Resources Wales, although the Wye bridge in the town remained closed.