Mr Brewer says with the underground infrastructure not coping at the moment, it will be well short of what is needed to deal with the city's future growth.
Among the most serious traffic-related incidents was a three-car crash on the Auckland Harbour Bridge which closed one northbound lane this afternoon.
A car towing horses on a trailer broke down and the animals were removed from the trailer after growing anxious.
There were also reports of flooding at the ASB Showgrounds.
The MetService has issued a weather warning for tomorrow, with storms expected to hit across the North Island.