Significant financial support must be given by the government to people and businesses besieged by flooding, the Sheffield City mayor has said.
In a letter to Prime Minister Boris Johnson, Dan Jarvis also called for a summit to discuss the "resilience of the region to future flooding".
More than 100 weather warnings remain in place around the country.
Meanwhile, the Environment Agency said people were trying to steal pumps used to move water away from flooded areas.
Mr Jarvis said 4,220 homes had been affected in South Yorkshire, leaving a "devastating impact" on communities.
Fishlake, near Doncaster, has been one of the worst hit with hundreds of homes submerged following the downpours which started last week.
While the mayor welcomed measures announced by Boris Johnson on Tuesday, he said "given the scale of damage in some of the most deprived parts of the country, it is concerning that this assistance was not forthcoming sooner".
Mr Jarvis's letter, written on behalf of several councils in South and West Yorkshire, said: "There is now a clear need for further concerted, integrated and decisive action in the short, medium and long term for those affected.
"In particular, consideration must also be given to those without insurance or whose policies have been deemed in-valid amidst these circumstances.
"To help out communities get back on their feet, it is imperative that this is provided as quickly as possible."
The prime minister's spokeswoman confirmed Mr Johnson had received the letter and would be sending a response "in due course".
Mr Johnson has faced condemnation for his response to the floods and for failing to act sooner.
It came amid criticism from Labour and the Liberal Democrats who said he should declare a "national emergency".
Laura Gordon, Liberal Democrat prospective parliamentary candidate for Sheffield Hallam, said Mr Johnson "must apply" for money the European Solidarity Fund to help people and invest in better flood defences.
Ian Walker, Conservative prospective parliamentary candidate for Sheffield Hallam, stressed the need to continue investing in flood defences and measures to tackle climate change.
He added: "One of the key things when people get flooded is the problems with insurance and getting it renewed.
"The government needs to step in and look what can be done to help people get cost effective insurance."
Soldiers are no longer helping the relief effort in South Yorkshire but the Ministry of Defence said 400 personnel remain on standby if the flooding increases.
The Environment Agency said 38 pumps had been used in Fishlake and half the houses were now free from water, but it would take about six days to clear it completely.
Pete Fox, from the agency, said homes in the village could "possibly be clear of water" by Sunday.
Water levels at the River Don were "now dropping", he added.
Flooding in Kirk Sandall, Doncaster, caused disruption to rail networks with TransPennine Express services between Sheffield and Scunthorpe being suspended.
As efforts to clear up the devastation continue elsewhere, the Environment Agency said people were trying to steal the pumps being used to move water away from flooded homes in South Yorkshire.
In a video posted to Twitter, Martin Christmas said: "Unfortunately we've started to see some criminal activity trying to steal our pumps and steal our pallet barriers."
Mr Fox said the agency had stepped up security patrols after an "attempted theft of a cluster of pumps" on Thursday night.