Gareth Toby Waller, 29, was the sole occupant of a vehicle that left Burdon Rd, near Geraldine, and rolled into the Waihi River about 6.45pm.
He died at the scene near the family property, between Burdon Rd and Tripp Settlement Rd.
Mother Annette Waller said she did not know what to say because it was "too raw at the moment".
Mr Waller is understood to have worked for the family business, Waller Direct Drilling.
Police investigations are continuing and the death will be referred to the coroner tomorrow.
The official holiday road toll stands at five after two other fatal crashes yesterday and another this afternoon.
The first after the start of the official holiday road toll period at 4pm on Friday came when a car ran off New Brighton Rd and into the Avon River in Christchurch about 12 hours later.
The second was in Taranaki after a car and light truck collided on State Highway, south of Waitara, soon after noon yesterday.
A woman who was the only person in the car was killed. Two people in the truck were uninjured.
Speed and alcohol were not believed to be factors.
An earlier fatal crash in Waiuku, south of Auckland, has been excluded from the official total because it was a result of medical rather than driving-related reasons.
The driver was flung from a car that drifted off the road and hit a totara tree about 8am yesterday.
Also yesterday, one person suffered critical injuries and four others moderate injuries after a late afternoon two-car collision on State Highway 1 at Kawakawa in the Far North.
Police said the vehicles were travelling towards each other and it appeared one veered onto the path of the other.
Meanwhile, a woman is in a serious but stable condition in a high dependency unit after suffering multiple injuries near Aoraki/Mt Cook yesterday.
She was airlifted to Dunedin Hospital after the crash on State Highway 80 about 4.30pm.
Two others were airlifted to hospitals in Christchurch and Timaru with multiple moderate injuries.
