In an act of "drunken stupidity", Daniel Martin Kornaus turned on two fire hydrants in an inner-city Brisbane unit complex while visiting a friend.
Kornaus didn't realise each hydrant activated pumps that delivered 1000 litres of water per minute.
They were shut down after half an hour but the damage had been done.
By the time emergency services arrived, seven of the Woolloongabba building's 13 residential floors were flooded.
Water was flowing out of the elevators.
Damage caused to the building by the February 2021 incident was estimated at more than $500,000.
That did not include the residents' significant financial losses.
Tenants in 52 of the complex's 92 units were forced to vacate for more than a week after suffering property damage.
Kornaus, 26, told police he was "black out drunk" at the time.
"It was a drunken, stupid, inexplicable and tragic error of judgment which had profound consequences," defence barrister Dan Boddice said.
The Brisbane District Court heard the building's management was notified of flooding about 3am.
After police studied CCTV footage, it was discovered Kornaus had turned on hydrants located in the stairwell on the sixth and seventh floor.
He had been visiting a friend on the sixth floor.
"It's only good luck I suspect that you didn't do this on the 11th or 12th floors and caused more damage," Judge Michael Byrne said.
Crown prosecutor Edward Fleetwood said Kornaus' "inexplicable behaviour" also included stealing 11 fire extinguishers from the building and putting them in a vehicle parked downstairs.
He also tore down fire evacuation notices around the complex and hit a vehicle in the downstairs car park with an extinguisher.
Asked by Judge Byrne if the car had been targeted, Mr Fleetwood said: "No, there is no rhyme or reason to it."
The court heard Kornaus had struggled with alcohol issues.
"He's come to the conclusion that it (alcohol) is just not for him because he can't moderate," Mr Boddice said.
Judge Byrne said it was clear Kornaus did not consider the consequences of his actions at the time but added that "you've got to wear the end result".
"This was drunken stupidity. A couple of moments of madness has caused bad results," he said.
"You are going to need some help with your alcohol...if you don't, I suspect you will keep coming back to places like this."
Kornaus on Tuesday pleaded guilty to five charges including wilful damage.
He was sentenced to 18 months in jail, suspended for 18 months with two years probation.
