Watchdog contacted Rotorua Aquatic Centre staff and the police, he said.
Clean-up took place early this morning, and replacement glass and an electrician have been organised to repair the damage to the automatic door.
He believed no one entered the centre as nothing had been touched and the internal alarms were not activated.
Police and Watchdog were now reviewing CCTV footage.
Another incident happened at takeaway shop, Oppies on Fenton St just before 4am.
A police spokeswoman said it appeared soft drinks were taken.
The next incident was about 40 minutes later with a report of a smashed window at Farmers on Amohau St.
Backdoor, on Tutanekai St, had its window broken by a brick about 6.45am.
The store's second in charge, Jayda Nathan told the Rotorua Daily Post the brick left a hole in the window and a bit of glass in the store, and they were fortunate the window did not shatter.
Nathan said the same thing happened last year, except the whole window smashed and a mannequin was stolen.
Police are still working to determine whether the incidents were linked.
Hospitality NZ Bay of Plenty branch president and Hennessy bar owner Reg Hennessy said the break-ins were "disgusting".
"Businesses are already going through a tough time," he said.
He said the attacks on businesses such as Farmers, Backdoor, and the Aquatic Centre was particularly concerning as he believed it showed the criminals were becoming more brazen.