A report prepared for the Auckland City Council says lessons from previous power cuts seem to have been ignored, and warns of disastrous consequences if there is a fault.
The council's city development committee will vote on Thursday on whether to make a submission to the Electricity Commission highlighting network infrastructure concerns.
The report, by council officers, says power north and west of Auckland is almost entirely dependent on twin overhead lines circuits between Otahuhu and Henderson.
It says the collapse of just a single tower would see power being cut for days.
Last week, power cuts in Auckland affected about 74,000 households and businesses in eastern suburbs and Newmarket, Onehunga, and Manurewa.
Rodney District Council, north of Auckland, supports any move to ensure a secure supply of electricity to feed its region and others.
The council's assistant chief executive Warren MacLennan says the network's precarious nature has been a reality for some time.
The Northland Chamber of Commerce also says a secure electricity supply is crucial.