The Prime Minister tonight pledged to do everything he could to help the flood-stricken communities of the Somerset Levels but warned solutions would take some time.
David Cameron's decision to come and see for himself the devastation caused by weeks of flooding coincided with a trip by beleaguered Environment Agency chairman Lord Smith to the area, where he faced furious residents and calls to quit.
Mr Cameron travelled to the Somerset Levels via helicopter - meaning he was able to view the region's 65 square miles of submerged land first hand.
The Prime Minister stood in deep flood water in a pair of Wellington boots to survey the damage to Tony Davy's farm in Fordgate.
"It's a biblical scene," Mr Cameron said.
"The scale of it here in Somerset is immense when you think of how many square miles are under water.
"Clearly people here have faced a very tough time and continue to face a tough time and that's why we have got to do everything we can to help.
"So more pumps, we brought in more pumps, more help from the emergency services, more help is there, money to help Somerset get back on its feet, the money is there, the Army coming in to help, whether it's helping with sandbags, which they've been doing over the last 24 hours, or looking to see whether temporary bridges can be put in place.
"Everything that can be done will be done and I'll make sure that happens.
"There are always lessons to learn and I will make sure they are learned but Cobra has been sitting in almost permanent session so we can bring the whole resources of Government, the country, the military to bear."
Mr Cameron admitted that the decision to stop dredging the Tone and Perrett rivers in the 1990s was "wrong" and a period or more "intensive" dredging was needed.
"I've said when the water levels come down and it's safe to dredge, we will be dredging to make sure these rivers can carry a better capacity of water so there are lessons to be learned and I'll make sure they're learned," he said.
"These are difficult times clearly across the South West with real needs. But these things are going to take time - I don't want to make any false promises to people.
"We will do everything we can, the resources are there, the money is there, the councils will get the money from central government, the military are on standby to help where they can."
Earlier in the day, Lord Smith, who was making his first visit to the Levels since the flooding began at Christmas, ignored calls to quit after being confronted by residents who were angry he was refusing to apologise.
The under-fire Labour peer said: "I have no intention of resigning because I'm very proud of the work the Environment Agency and its staff have been doing right round the country in the face of the most extreme weather."
Local resident Jim Winkworth, a farmer and pub landlord, said he was "bloody mad" at his refusal to apologise.
"We thought that's the least he could do today and he's not apologising or admitting any liability," Mr Winkworth said.
"He hasn't come down here to apologise, which is what he should be here for. If you apologise it means you're admitting you got it wrong, I made a mistake, I'm sorry, I messed up but he's not fit to do that."
And angry farmer Julian Green confronted Lord Smith live on television and demanded that he resign.
Mr Green told him: "We just need something done, it's as simple as that.
"Our house is going under, it's as simple as that. I am one of the last ones. Moorland's gone, which I am sure you are aware.
"At least it's nice to see this time that you've got a pair of wellies on."
Asked what he wanted the chairman of the EA to do, he said: "Sort the rivers out."
Mr Green said he agreed with calls for Lord Smith's resignation, saying: "I am not the only one round here who would like him to resign. We have had this for too long, we've had this for five weeks."
But the agency boss refused to quit, and said: "As I have said before, I have no intention of doing so because there is important work to be done, getting the dredging done as soon as possible, and getting the long-term solutions for the Somerset Levels sorted out."
Earlier, local Tory MP Ian Liddell-Grainger said he had not been given any details about Lord Smith's visit and branded him a "coward".
"I will tell him what I bloody well think of him - he should go, he should walk. I'm livid. This little git has never even been on the telephone to me," he said.
"He's a coward."
Local councillor Julian Taylor, who was evacuated on Wednesday, said: "I think it's all very well for politicians in Westminster to send condolences and say that they're going to do things, but the issue is now that we're reaping failure of something like about 50 years of bad maintenance and short-term policies."
Somerset County Council leader John Osman, who has also visited flood-hit residents, said: "To see families forced to leave their homes because of floodwater is just devastating and I can only imagine what they are going through.
"The message from everyone I met came across loud and clear - more needs to be done, and I am determined that the views of those worst affected will be heard further up the line."
Mr Cameron and Lord Smith's visits - a week after Environment Secretary Owen Paterson was heckled by local residents - came as Royal Marines were helping evacuate some 140 properties in the village of Moorland.
Another night of heavy rain overwhelmed local flood defences and, despite advice from police, a handful of people have chosen to remain in their homes.
As residents have struggled to cope with the rising water, police arrested three men on suspicion of stealing fuel from near the cut-off village of Muchelney.
The arrests follow the theft of 600 gallons of domestic heating oil from a farm in Moorland and the theft of two fire service quad bikes from Burrowbridge last week.
Around 5,000 properties have been affected by flooding across the country, including 40 in Somerset, and more flood misery is expected in the coming days, with severe weather alerts in place for parts of England, including the South East, South West and Wales as more wet weather is forecast.
The EA was warning that large waves and strong winds could cause further significant flooding along the coastline of Devon and Dorset this weekend.
Transport Secretary Patrick McLoughlin travelled to Devon to see the Dawlish damage, which is going to take around six weeks to repair.
His visit coincided with an announcement from transport operators that flood-hit travellers in the south west are to get more flights and coach services and special rail fare offers.