Police are on the hunt for two men who broke into a Myrniong reservoir and stole a number of electronic water-level monitors.
The pair cut and removed the chain on the gate to the tower bridge at the Pykes Creek Road reservoir.
Water reading monitors were damaged and several were stolen.
Police have released images of the men they believe may be able to help with their inquiries.
Information to CrimeStoppers:1800 333 000