A police spokeswoman confirmed ambulance staff were also responding.
Heavy rain is falling in the area and a Hawke's Bay Rescue Helicopter spokesman said the helicopter had been unable to make the journey due to the hazardous conditions.
Fire and Emergency NZ Hawke's Bay area commander Ken Cooper said a fire engine from Taupo was on the scene.
Two fire engines from Napier, along with a level-three advanced rescue team from Hamilton are also en-route to the accident.