Site access will be altered so the main access will be through the Pine Road and Della North Road access point, rather than through the intersection of Neaves and Della North roads.
Some long-term residents along Pine Road opposed the new plan at a recent City of Swan council meeting, saying additional traffic and increased noise from the water park had disturbed their peace and potentially devalued their properties.
The council added a condition that Outback Splash owners would have to submit an acoustic test to control the music volume.
Pine Road resident Shane Meakins said he bought his property in Bullsbrook 30 years ago for the tranquillity, but that was taken away when the water park started operating.
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READ NOW"I live 300 metres away" you can't even sit and watch television on a Sunday afternoon," he said.
"Doof, doof, doof all day long" it's affected the rural amenity in a negative way."
The first stage of Outback Splash opened in January last year but the owners previously told The Advocate there were much bigger plans for the water park.