The crash killed Jesse Uncles, and seriously injured passengers Kayden French and Stephen Palmer. Mr French, 22, received life threatening injuries and remains in hospital nearly eight months after the crash.
A blood sample taken after the crash showed Walker had a blood-alcohol level of 218mg per 100ml - the legal limit at the time was 80, which means he was almost three times over the limit.
Judge Bridget Mackintosh says Walker admitted to drinking seven cans of beer, as well as a can from a beer funnel and a swig of spirits.
In a statement read out to court, the parents of Mr Uncles said the night he died is a continual nightmare.
Dennis and Helen Uncles say his injuries were so bad they couldn't even see him to say goodbye and the coffin had to be closed.
They say Jesse was a kind and charitable young man, who planned to propose to his girlfriend on the day of his funeral.
His last words not long before the crash happened were "I love you mummy".
Leanne French, the mother of injured passenger Mr French, said for seven weeks her son clung on while on life support with a mangled, beaten up body in ICU in Wellington Hospital.
She says he is still in hospital and they don't know whether he is going to fully recover.
Crown prosecutor Steve Manning said Walker showed a cavalier disregard for himself and his passengers, and other members of the public on the road that night.
Mr Manning said it was an accident waiting to happen.
Walker's lawyer Eric Forster said his client had a previous drink drinking conviction in 2014, and the second time he was caught has ended in absolute calamity.
Mr Foster said he has real remorse and is deeply upset that he's lost two of his good friends.
Walker was jailed for three years and nine months and disqualified from driving for seven years
