"We took what we had at home, and now it's time to help. It's emotional, it gives you goosebumps," 55-year-old engineer Federico Martinez told AFP as he clutched a shovel on his shoulder.

While the eastern Mediterranean city of Valencia was spared by the floods that have killed more than 200 people, suburbs lying a few kilometres away drowned in a destructive sea of sludge.

Hundreds of Valencia residents rushed to the streets carrying what basic necessities they could to make for the stricken zones on foot during a public holiday.

As they crossed the bridges on the city's outskirts, the once picturesque agricultural landscape slowly transformed into a mud-covered wasteland.

"Thank goodness that Spain stands together," said Alicia Izquierdo, who with her sister Marta pushed two shopping trollies stuffed with food.

They were headed to their brother's home in Paiporta, a Valencia suburb at the heart of the destruction, but getting supplies from the supermarket was a challenge during severe transport disruption.

Tamara Gil did not think twice before walking the three kilometres (2 miles) of fields and industrial estates separating Valencia from Paiporta, where she works as a teacher.

A worried Gil, pushing a cart of water and other essentials, said she "knows nothing" about her students or their families despite a night of fruitless telephone calls on Tuesday when the flooding peaked.

- 'Toll on the elderly' -

Once in Paiporta, where thousands of survivors are making do without power or water, the volunteers were greeted with a dystopian scene of mud and overturned cars.

The authorities have urged people to stay at home, warning that the well-intentioned masses of volunteers risked blocking the emergency services.

But the helpers kept coming, many loading bags and water containers at the municipal hall where dozens of people queued at an aid distribution point.

Ramon Vicente, 73, and his wife Fausti lived through a 1957 flood that left dozens dead in Valencia and scarred generations of locals -- but this week's catastrophe has eclipsed it.

"I remember that and the city needed a lot of time to recover," Vicente told AFP, worrying about where to secure food, water and medicines which they usually receive from a now inaccessible hospital.

"This is going to take a toll on us elderly."

- 'Lack of organisation' -

Paiporta's streets were a hive of activity on Friday as residents and volunteers shovelled out waves of sticky mud from homes and shops.

In the town's main church, volunteers bailed out bucketfuls of water that still reached their ankles.

But some feel a lack of support from the authorities is undermining the wave of solidarity washing over Valencia.

"There's a lack of organisation. People want to help, but there's no one organising," said Montse Fernandez, a volunteer from a town north of Valencia who was clearing mud from a street in Paiporta.

"There aren't enough firefighters, the shovels haven't arrived," added Paco Clemente, a 33-year-old pharmacist.

Holding her snoozing month-old baby in her arms, Estefania Garcia felt fortunate despite the hellish past few days.

"We have lost the cars, part of the house, but it's fine, we're alive," she said.