Fire and Emergency New Zealand is also urging people in flood impacted areas of Napier to take extra care using electrical appliances.
Cooper said do not use your power or gas until your supplier has checked and informed you that it is safe to use.
"If you buy a second-hand electrical appliance, get it checked and tested before you use it," he added.
Cooper said there are 30 uninhabitable houses on or around Napier Hill, with a further 37 are in Marewa, Maraenui and Pirimai.
Urban Search and Rescue and Napier City Council engineers aim to complete their assessments of properties on Friday.
"Multi-agency teams also continue to check people's welfare and wellbeing in the most severely impacted suburbs of Maraenui, Marewa and Pirimai and to coordinate support to affected residents," Cooper added.
Wise also admitted water pumps did not operate for a short period of time due to a power cut: "It was a very short period of time as generators were used straight away."
She said the council was still in an information "gathering" stage, and that the areas affected in Napier were "many".
Impacted residents seeking assistance can call 0800 422 923 or visit www.hbemergency.govt.nz and www.napier.govt.nz