He said Auckland Council had been contacted to remove the power pole.
Mr Greenhalgh said power company Vector had been advised of the downed pole about 10.52am. No power was affected.
The cause of the accident was unknown at this stage, he said.
Mr Greenhalgh said there was one police vehicle on scene but wouldn't stay long. "There is no risk to the public," he said.
Auckland police were kept busy last night attending a score of minor car crashes around the region.
A police spokesman said this morning that there had been about 20 crashes, mostly "bumper to bumper type stuff".
Nobody was seriously injured, he said.
It's wet in the City of Sails and police are asking drivers to take care, drive to the conditions and reduce their following distances.
"It looks like [the rain] is going to be set in for the remainder of the day," the spokesman said.
MetService is forecasting rainfall for the whole day, getting heavier this evening.
In Northland, one person was briefly trapped in a car crash this morning.
Emergency services were called to Kaiwaka-Mangawhai Rd before 8am after a van and a car collided near the intersection with Tara Rd.
A police spokesman said the van ended up on its side.
"The occupants are all safe and well. There's no serious injuries."
The van's driver was briefly trapped after a door jammed, but firefighters managed to "release" the door.
"We're not expecting any road closures or anything like that," the spokesman said.
"Thankfully everyone is safe and well, only minor injuries and perhaps a little bit of shock."
The serious crash unit has not been called and police at the scene were investigating.