Public anger is mounting over the disaster that has killed at least 217 people with dozens of others unaccounted for.
Almost all the deaths occurred in the Valencia region and more than 60 in the suburb of Paiporta.
The search continues for bodies in eastern Spain, with dozens of people still unaccounted for. (AP PHOTO)
The army sent about 5000 soldiers at the weekend to help distribute food and water, clean up streets and guard against looters and a further 2500 would join them, Defence Minister Margarita Robles told state-owned radio RNE.
A warship with 104 marine infantry soldiers as well as trucks with food and water arrived in Valencia port on Monday even as a strong hailstorm pummelled Barcelona some 300km to the north.
On Monday evening, Spanish minister Felix Bolanos from the Socialist Party said Tuesday's cabinet would declare some of the worst-hit villages by the floods in the regions of Valencia, Andalusia, Castile La Mancha and Catalonia as "severely affected areas" so they could be entitled to emergency funds.
He said the government would approve a package of relief measures to help people cope with the situation.
Rescuers used drones and water pumps to search and clear underground car parks and garages.
They also scanned river mouths where currents might have deposited more bodies.
The Spanish government has promised relief package to help flood-affected residents. (AP PHOTO)
Opposition politicians accused the left-wing central government of acting too slowly to warn residents and send in rescuers.
The regional head of Valencia, Carlos Mazon, said the Hydrographic Confederation of Jucar, which measures the flow of rivers and ravines for the state, had cancelled a planned alert three times.
But Madrid said the CHJ did not issue flood risk alerts, which were the responsibility of regional governments.
Locals criticised late alerts from authorities about the dangers and a perceived delayed response by emergency services.
But General Javier Marcos, commander of the army's emergency response services, said he had ordered 500 soldiers to be deployed within 15 minutes of seeing the flood warning last Tuesday but they were not able to enter hard-hit areas.
"The degree of destruction is so great that mobility is limited," he said.
King Felipe faced a torrent of abuse from residents about the government's response to the flood. (AP PHOTO)
"It is so complex that it requires two things: discipline and patience."
On Sunday, some residents in Paiporta threw mud at Prime Minister Pedro Sanchez and King Felipe and his wife, Queen Letizia, chanting: "Murderers, murderers!"
The prime minister was also struck during the protests, Interior Minister Fernando Grande-Marlaska said in an interview on TVE, blaming a handful of extremists for the trouble.
Locals in Paiporta said anger boiled over because they felt authorities were using them for a photo opportunity.
The midweek torrential rains caused rivers to swell, engulfing streets and ground floors of buildings, and sweeping away cars and masonry in tides of mud.
It was the worst flood-related disaster in Europe in five decades.
