CORUNNA Lake is open to the sea after lake level trigger points were reached requiring an excavator to cut a channel.
Recent rains had raised lake levels to where they were impacting on the Old Highway, which forces National Parks that controls the lake entrance area to bring in an excavator, in this case driven by local contractor Rob Negus, to cut a channel.
Ranger Tony Baxter said it was preferable for these intermittently closed lakes to open of their own accord during flooding events.
The opening on Thursday evening was timed one hour after high tide to allow the highest flow out possible, he said.
It is illegal for anyone other than authorities to artificially open lakes.
Corunna only opened briefly but naturally during the big rains last year.
It is however becoming visibly more choked with silt and sediment particularly between the highway bridge area and the entrance.