Flooding in Mount Maunganui, Papamoa and Te Puke created chaos this morning.
Fire fighters have already responded to 28 flooding-related calls in the area this morning.
A Northern Communications Center spokesman said there was a rush of calls when the first thunderstorm hit between about 7am and 9am.
About 15 calls were backed up at one stage but most were only minor flooding and subsided when the rain eased.
Tauranga police Sergeant Simone Mills said there had been surface flooding on Maunganui Rd, Tui St, Links Ave and Tay St.
Metservice reported 41.4mm of rain fell in Tauranga between 8am and 10am this morning.
Another 7mm is expected between noon and 2pm with a total of 22.1mm expected by midnight.
State Highway 36, the Tauranga direct route, will remain closed for the most of the day due to slips. Roading contractors are working to clear the road and ensure road safety.
Traffic can divert at Ngongotaha to State Highway 5 and across the Kaimai Range or travel through Rotorua CBD to State Highway 33 toward Te Puke.