Watch Gary Smith, holidaying in the area, talk about conditions near the crash scene in Powys.
A 17-year-old girl has died after a 4X4 car left a flooded forestry track and overturned into a river in Powys.
A man in the vehicle had to walk several miles to a farm to raise the alarm after Friday's incident near the Llyn Brianne reservoir.
Hundreds are mopping up after four inches of rain fell in 48 hours but problems eased on Saturday.
The teenager who died near the Powys-Ceredigion border was a tourist from the south east of England.
She was airlifted to Bronglais Hospital, Aberystwyth - along with a male and another female suffering from hypothermia.
Three helicopters were used in the rescue on a remote forestry track north of Llyn Brianne reservoir.
Casualties were flown to Bronglais hospital, Aberystwyth
Insp Robert Price, of Dyfed-Powys Police, said that flood water from the river had caused the vehicle to "lose its footing" and tip into the river.
Emergency services were alerted at about 1745 BST on Friday.
Inspector Eric Evans told BBC Radio Wales later: "A man in the vehicle had to walk some distance in miles from the scene to the nearest property to raise the alarm.
"The weather conditions were extremely bad and it took him a long time. He must have been quite traumatised by his journey."
Gary Smith, who is part of a group off-roading for the weekend and had camped in the area, said he and his friends came across the 4x4 vehicle on Saturday morning.
He said yesterday's weather conditions were bad.
He said: "It never stopped raining from the minute we woke up yesterday morning until we got here last night and set up camp.
"The rivers were gushing like mad - you can't get any more water down there than what there is."
Elsewhere in the county, there were a few road closures overnight, particularly around Crickhowell.
The A490 near Welshpool was closed after flooding.
Dee-Ann Palmer has had her house ruined by flood water
Gwent Police and emergency services dealt with 88 flood-related overnight calls, with people moved from houses and road closures.
On Saturday, the rivers Monnow and Wye in Monmouth burst their banks.
In south Wales, there were incidents in Pontypridd, Caerphilly, Abercynon, Aberdare and Ystrad Mynach last night but the situation had eased by the morning.
A man was rescued by fire-fighters after falling into the River Clywedog near Wrexham.
Fire services across Wales were not dealing with any fresh incidents so far on Saturday.
Businesses and residents in Mill Road, Ely, Cardiff were mopping up after overnight flooding after the River Ely burst its banks. A newsagents and cafe were among properties damaged.
Environment Agency Wales advised people to be vigilant as river levels remain high and warning that short periods of rain could cause problems.
At 1630 BST, there were 20 flood warnings and nearly 30 flood watches in force on rivers across Wales.
John Mosedale, the agency's flood risk manager for Wales said: "Our clear message is that people need to be very careful near water. We can not emphasise enough how dangerous flowing water can be."
"Our flood defences across Wales have stood up well in the face of what can only be described as a pounding over the last few days. "
Mopping up was continuing in the south Wales valleys, which was worst affected during Friday's storms.
It was particularly busy around the Pontypridd, Church Village, Llantrisant, Aberbargoed and Abercarn areas with South Wales Fire Service dealing with more than 500 flood-related calls during the course of the day.
One of the day's flood victims was Fred Jenkins, of Ynysboeth in the Cynon valley, whose home was overcome by a 4ft (1.2m) wall of water.
Before we could do anything it had entered the house. I couldn't do anything
The rainfall also caused chaos in the leisure sector with the ninth annual Pontypool Jazz in the Park 2008 festival being called off after the events various venues were flooded by torrents of water.
More than 50 concerts were due to take place from in four sites around Pontypool Park over the weekend but the heavy rain and local river bursting it banks ensured the event had to be cancelled on the grounds of public safety.
A spokesman for Torfaen County Borough Council said: "A judgement had to be made and, unfortunately, it had to be cancelled.
"It's not been reorganised for another date because the event was due to have more than 50 acts playing and we couldn't rebook that number of acts any time soon so the event has been lost for this year.
"It was going to be a superb programme this year and losing it to the weather is a terrible tragedy for us."
There was some good news for those looking to have a good time despite the weather with the gay and lesbian festival, Cardiff Pride 2008, refusing to buckle under the bad weather.
Waterlogged grounds forced organisers to cancel the festivals main showcase event in Coopers Field but after talking to local council officials a scaled-down version of the event will go ahead from midday today.
The River Usk in Brecon, Powys, on Saturday morning
Cardiff Pride spokesman Haydn Price said: "As a result of the bad weather we have spoken to Cardiff County Council and they have agreed to let us open the street party in Churchill Way from midday.
"So it's not all doom and gloom. It's not going to be on the same scale but at least we're going to be putting something on for those that had been coming to Cardiff for the event.
"But we'll be back as we've already booked the venue for September next year."
However, the National Mud Festival of Wales at the Wildfowl and Wetlands Trust National Wetlands Centre Wales near Llanelli will not be affected by the rainfall.
Now in its seventh year, the event will be revelling in its wet surroundings teaching the public about the importance of the mudflats in the Burry Inlet and what the trust is doing to preserve them.
Throughout the weekend there will be lots of activities illustrating the uses of mud such as mud hut building, mud sculpting and the chance for people to join in the annual Tug of Mud competition.
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