"It looks like an angle grinder of some kind has been used to get in.
"The funny thing about it is they (thieves) shut it back up again so it looked like everything was normal."
Cricket Whanganui had recently welcomed director of coaching Greg Smith and female development officer Verity Johnson to the fold, who had been doing a lot of work in the community, Bowman said.
"In three weeks we've seen around 500 kids at eight schools.
"This Friday our all-girls sessions are starting and in a few weeks' time, we're going to have 'Women's Smash' which is open to females of any age who want to play cricket.
"Now we can't even mow the pitches. It's that 'stone-in-your-belly' stuff."
Bowman said the missing mowers were distinctive and could be identified by their wide blades.
"Maybe someone is setting up their own lawn business and thought they would borrow our stuff.
"The worst part about the tools being stolen is that they belonged to the father of our groundsman Steve (Meredith), who passed away earlier this year. That's the sort of stuff you can't replace."
Cricket Whanganui leases the building from the Whanganui District Council and is responsible for it.
The upper pavilion is alarmed but no security cameras are installed.
"We still aren't sure exactly how they got all this stuff out of the park.
"Those mowers are two or three times the standard size across. You would have had to get them up onto a truck or a trailer."
Bowman said this week's break-in was the third at the pavilion in the last 12 months.
Fuel and the battery from the pitch roller had been taken, followed by an attack on a storage shed.
The new roller battery was stolen from the greenkeepers' shed during the latest incident.
"Over the offseason we even had the wheels of our sight screen stolen, so there's probably a go-kart around town somewhere sporting some fairly chunky tires on it," Bowman said.
A police spokesperson said inquiries into the incident were ongoing and they would be interested in hearing from anyone that had information.
In 2017, a grass roller was started up and crashed into the side of a building on the other side of Victoria Park.
That building is used by the Wanganui Harrier Club.
A Harrier spokesperson said it had been broken into and damaged twice this year.
"Ripping people off and damaging property is easy to do, but decent people choose not to.
"They don't understand that there are victims involved. We are a club that puts events on for the city and for people in the community.
"There is a cost to us and a cost to the council, who have had to replace the whole mechanism in the slider door."
Bowman said Sport Whanganui was in contact with local bowling clubs to see if the organisation could borrow some of their equipment.
Premier 1 cricket, due to start this weekend, may be moved to Whanganui Collegiate if the Victoria Park pitches can't be finished in time.