The price of gas is set to go up for South-West households, commercial and industrial customers including those located in Busselton, Bunbury, Harvey and Capel.
The Economic Regulation Authority released its final decision for ATCO Gas Australia's revised access arrangement for the Mid-West and South-West Gas Distributions Systems.
Under the ERA's decision, the average cost for residential customers to access ATCO's network will go up in real terms by 5.77 per cent in 2020, and around 0.5 per cent each following year from 2021 to 2024.
This charge makes up around 30 per cent of the average household gas bill.
ATCO owns and operates the Gas Distribution Systems, which services around 750,000 customers also taking in Geraldton, Pinjarra, Brunswick Junction, Mandurah and Perth.
ERA chair Nicky Cusworth said the authority had carefully considered the effect on consumers and substantially reduced the price increases from the amount originally proposed by ATCO.
"The State Government sets the maximum amount that small use customers such as households and small businesses can be charged for their gas, and that capped price goes up by the rate of inflation each year," she said.
"Customers paying the capped price will probably not see any change in their bill, but gas retailers may choose to reduce the size of discounts on offer to recover some or all of the increase.
"Thanks to increased competition from gas retailers, lower gas prices and lower ERA-approved network tariffs over the previous access arrangement, Western Australian gas consumers are still in a better position than they were five years ago."
ATCO's revised access arrangement will start on January 1, 2020 and run until December 31, 2024.
Mitsubishi Electric's recent Australian Home Trends Report found that 43 per cent of Western Australians were extremely concerned about the rising cost of energy and how it would effect their household budget.