Christchurch City Council says its unsure exactly how many residents across the city could be classified as highly vulnerable to severe flooding.
Earlier this week the mayoral taskforce created to find short term solutions for properties suffering from repeated flooding found 56 have been flooded inside on more than two occasions in the past six months.
Council land drainage operations manager Mike Gillooly says resident feedback has been constant since Monday and the number of those considered most vulnerable could have doubled.
Mayor Lianne Dalziel says the numbers were always going to change .
She says the figures and the criteria the Taskforce used to determine the levels of vulnerability have now been made public and, in turn, public response will help the council revise them.
Ms Dalziel says it is still unclear how costs will be apportioned between home owners, the EQC, and the council.