A Shepparton East company has been ordered to pay more than $10 000 in compensation, costs and placed on a two-year good behaviour bond.
The company was found guilty in Shepparton Magistrates' Court for taking 85 megalitres without authority in the 2017-18 water season.
Goulburn-Murray Water said it provided repeated warnings and issued a caution to correct the overuse of water.
G-MW said in a statement the water was valued at $106 a megalitre and the company could have paid more than $50 000 if the theft happened at current prices.
General manager water delivery services Warren Blyth said the fine served as a "timely reminder" water was only available to entitlement holders with an allocation.
He said G-MW has a process that alerts customers, warns them of any overuse and cautions them against continued non-compliance before legal action was required.
“We have an obligation on behalf of all entitlement holders to ensure customers do the right thing and not enter into any overuse of water,” Mr Blyth said.
“If customers persist in doing the wrong thing, we will take action.”