The 27-year-old said through his lawyer earlier in court it was a “foolish mistake” he now wanted to move on from.
The tradesman and team manager, who was well-regarded by his employer, is now subject to an interlock order and plans to have the device installed in the work vehicle he drives.
An interlock device prevents a vehicle from starting if it detects alcohol on a driver’s breath.
Riach was stopped by the police while driving late at night on February 24 on a main street near central Nelson.
An evidential breath test showed he was almost four times the legal limit, with a reading of 980 micrograms of alcohol per litre of breath.
The limit is 250 micrograms.
Riach’s lawyer Tim Spear said he had got safely home after drinking that night, when he got a text from a “lady friend” who asked him to pick her up and take her home.
They were on the way home when stopped by the police.
“He said it was a stupid thing to do,” Spear told the court.
Judge Jo Rielly said the alcohol level recorded was “extremely high”, and in the explanation provided to police Riach had admitted having had “a lot to drink”.
“It was a very stupid risk to take, and one I imagine you now wish you hadn’t,” Judge Rielly said.
She said Riach would have been “significantly impaired” and at his age, he should have known better.
Judge Rielly noted a letter from his employer indicated he was very successful in his job and that his role as a manager for a local trades business included oversight of staff.
“I’m pleased your employer is so supportive, but you need to sort out your attitude to drink driving,” Judge Rielly said before sentencing Riach to community work.
Today, Judge Tony Zohrab amended to sentence and fined Riach $1500 plus court costs, but maintained the order for the mandatory 28-day disqualification before he could be issued with an alcohol interlock licence, which meant he could only drive a vehicle fitted with an approved alcohol interlock device for at least 12 months.
Riach would then be subject to a zero alcohol licence for three years.