A WOMAN has been flown to Gold Coast University Hospital after sustaining serious injuries in a single-vehicle crash.

Emergency services were called to the scene on Rushforth Road, South Grafton at 8.40am this morning.

The car hit a street pole at the intersection of Tyson St, and came to rest next to a fence adjoining South Grafton High School's back oval near the new Clarence Valley Council depot.

"There were three patients; two children who were transported to Grafton Base Hospital and a woman flown to the Gold Coast with serious injuries," NSW Ambulance duty manager Scott Ackton said.

It is believed the woman had sustained head injuries.

Emergency services were initially concerned about a potential livewire on the ground as a result of the driver hitting the street pole.

However, an Essential Energy spokesperson  confirmed that no power outage occurred and crews have isolated the pole.