About 150,000 litres of water was lost when offenders attempted to steal water pumps from Bellbird Park recreation precinct in Drouin.
Police said offenders manipulated locks to access a shed at the Settlement Rd precinct. Pumps in the shed were dismantled and disconnected.
Some parts were stolen from the pumps but the pumps were left in the shed. Police believe they planned to return for the pumps.
The incident occurred between January 10 and January 13.
The pumps are owned by Baw Baw Shire Council and used for irrigation across the Bellbird Park precinct.
It is estimated about 150,000 litres of water was lost when the pumps were disconnected.