The total prize is made up of $22m from Powerball First Division and $333,333 from Lotto First Division.
Central Otago Mayor Tim Cadogan has said Alexandra was "buzzing" with excitement, "and everyone's talking in the community about what you would do if it was you [who won]".
The $22.3m winnings would buy 40 median-priced New Zealand homes or about 27 standard properties in Auckland.
But a former Lotto winner has some sensible advice for the country's newest multi-millionaire: Don't do anything rash with that $22m.
The winner offered these tips in 2016 to any lucky players who struck it big - think carefully before making any other big purchases.
The New Plymouth woman won $1m with Lotto first division two and a half years ago. She told the Herald the best advice she was given was to "sit back" and take the win in before making any big decisions.
"Really think about all your options. I made sure I got good financial advice too, which I definitely recommend."
Winning Lotto had changed her life by relieving financial pressure, but it had not changed her lifestyle.
She and her husband kept their house and both had kept working.
Lotto also advises winners to take things slowly after winning big, and recommends people don't quit their jobs overnight.
All major prize winners receive a copy of Lotto's winners book, which is packed with tips, tricks and information to help newly cashed-up Kiwis.
A big win conjures up elaborate fantasies of luxury holidays and designer clothes but a recent Lotto survey found a huge chunk of winners were using their money to help others.
Nearly half (46 per cent) of winners used the money to help out family members and 30 per cent helped their communities with random acts of kindness, food parcels and donations.
Holidays were still a priority however, with 31 per cent of winners taking trips, particularly to the Pacific Islands and New York City.
A smaller number, 23 per cent, indulged in shopping sprees and some splashed out on new cars and big screen televisions.
Since 1987, when Lotto began, hundreds of people had become instant millionaires.
Largest Powerball prizes won in South Island
• $22.3m, August 2018, MyLotto, Central Otago
• $22.2m, April 2016, MyLotto, Ashburton
• $20.5m, November 2012, Windsor Stationery and Lotto, Invercargill
• $20.2m, February 2012, Hornby Mall Lotto, Christchurch
• $18.2m, February 2017, MyLotto, Otago
- Additional reporting: Otago Daily Times