Two women and man managed to get out. The man and one of the women were airlifted to Waikato Hospital with moderate to serious injuries and the other woman was taken to hospital by ambulance, also with moderate injuries."
According to Westpac Rescue Helicopter records the car was travelling at high speed before the crash.
Mr Tooman said it was too early to determine the cause and police are investigating what part alcohol and speed may have played.
Resident Robin Halpin said some drivers treated Reservoir Canal Rd as a "racetrack" because it was long, flat and straight.
Another resident, Lorraine McDuff, said a 19-year-old died when a car crashed into the canal a year earlier.
"They speed down our road something horrific ... [That corner] is where they do all the burnouts. You see the tyre marks from the wheelies that they pull out."
Mr Tooman said the death took the district's road toll to 50, compared to 48 for the same period as last year.
He urged a conservative approach to driving ahead of the busy Christmas and New Year period.
The death has been reported to the Coroner.