Local flood managers told the group it costs between $75,000 and $250,000 either to raise a home and protect it from the tides, or to acquire it so the homeowner can move out.
Marc Becker, Sepa's duty flooding manager, said: "Rivers will remain high in areas that experienced a lot of rain yesterday but are expected to fall later in the day.
For days before the mine flooded, managers ignored water leaks that presaged trouble, according to preliminary findings by the State Administration of Work Safety.
'Flooding can never be prevented,' added Tim England, the agency's acting flood defence manager.
Mrs Susan O'Neill, flood risk manager, Environment Agency, for serv flood defence in Yorkshire and to north-east.
Amy Brandley, the Canadian County flood plain manager, said emergency crews had only just begun to assess the damage.
"Their levees have been altered without careful evaluation and no permission," said Scott Whitney, flood risk manager for the Corps Rock Island Districtt.
Jonathan Day, flood risk manager at the Environment Agency, warned at the weekend that the risk of flooding could continue throughout this week.
Clare Dinnis, national flood duty manager at the Environment Agency, said: "People in the south-west and north-east need to be aware of the potential for further flooding.
Ben Lukey, flood risk manager at the Environment Agency, said natural flood defences also improved water quality but was not suitable everywhere.
