Stawell Bowling Club are calculating the extent of the damage to the club's greens caused by vandals.
Police and crime scene officers attended the scene on Thursday and expressed disappointment at the act of vandalism.
"Between 4.45pm and 5.15pm on March 4, a number of person of interest have entered the premises through an unlocked gate, obtained rink markers and launched them onto the green," Stawell Sergeant Eddie Malpas said.
"When they have landed the edges have caused quite significant damage to the green."
More than 50 damaged areas were marked on the green.
"What might be a bit of mucking around for the people who have done it will cost a lot for the Bowls Club," Sergeant Malpas said.
"We have lines of inquiry we are following up at the moment."
Club president Andrew Sharp said he disappointed in what will now become a timely and costly exercise in repairing or potentially replacing the green.
"We have review CCTV vision and know the approximate ages of the vandals," he said.
"It's disappointing that those captured on the vision could have possibly used our facilities and had a great time during organised activities.
"We let community groups and organisations within the area use all of our facilities free of charge and supply volunteers.
"For people to then come over and trash the place - it's really disheartening."
Mr Sharp said no one will know for some time, the full extent of the damage.
"We can water it, roll it, brush it and try and see what it comes up like," he said.
"It could be two or three months before we know if the damage is repairable or if the green has too many marks in it and needs replacing.
"If parts can be repaired it will never be as good as it was."
Club greens director Neil Coates said he spends about two hours into the green each week and said it's a shame his hard work is undone it what might be mucking around for some.
"At the moment we are assessing what our options are and if the marks can be repaired," he said.
"Right now, I am in the process of preserving what's left of the green until we make an assessment and a decision is made at an upcoming board meeting about what our next steps will be."
Mr Coates spends time each week watering the green - keeping the sand down.
"If you don't water the greens all the sand comes to the top," he said.
"With the divots needing repairing, it can take a long time to build up the solid base underneath the hole and extra maintenance, care and water.
Mr Coates said the approximate value of a new green would be more than $100,000 - a figure to be determined and confirmed through quotes and research.
"We received a new green when the floods came through about six or seven years ago," he said.
"It's a really big job and although we are nearing the end of the bowling season we still have activities and competitions played weekly which will be impacted."
Mr Sharp said although the club is insured, there is still excess and added financial extras which will need to be considered.
"Using insurance means excess and that is funds which we shouldn't have to factor into a yearly budget," he said.
"We understand that accidents and mother nature can happen, that's why we have insurance - but this was no accident."
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