Goulburn Murray Water hopes to have identified the cause of two malfunctioning spillway gates at Laanecoorie Reservoir by early this week.
The reservoir had reached 100 percent capacity and was overflowing after solid rainfall swept the region over September 4 and 5.
But late last week the storage had fallen from 100 percent to 70.8 percent capacity after two spillway gates failed to automatically upright correctly after lowering to control overflow.
G-MW Regulated Systems acting manager, Andrew Shields, said that when Laanecoorie began overflowing after reaching capacity, numerous spillway gates automatically opened to assist in regulating overflow for dam safety.
However when the storage volume had spilled sufficiently the gates should have automatically uprightened, he said.
Instead two of them had failed to do so, reducing the Laanecoorie capacity to around 70.8 percent as at last Friday.
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