Blacktown Council has decided to adjust suburb boundaries within the area, with eight new suburbs created.
On Wednesday it was decided the change was necessary to cope with population growth in the area - particularly given the new train line in the area from 2019.
Locals from the area are petitioning the change, with residents of the newly-defined Marsden Park concerned about house prices as most of the amenities fall into the new area.
“About 6000 people had a say," Labor councillor Chris Quilkey said.
"I think that’s representative democracy at its finest. Most of those people I think will be satisfied with what we are proposing. As decision makers we make decisions.”