One of the charges on south-east Queensland water bills would be up to $80 more expensive in three years under draft recommendations handed to the state government.
The Queensland Competition Authority is reviewing bulk water prices for customers in 11 council areas, in an attempt to reach a common price across south-east Queensland.
Out of the 11 council areas, Sunshine Coast, Noosa and Redland City were yet to reach the common price, but all would be standardised by 2019-20 or 2020-21.
Under option one, the bulk water charge for an average south-east Queensland household would cost $488.80 per year by 2020-21, while option two would cost $489.44.
That was based on the indicative bulk water bill for an average household using 160 kilolitres per year.
For people living in Brisbane, Gold Coast, Ipswich, Lockyer Valley, Logan, Moreton Bay, Scenic Rim and Somerset councils, it meant an additional $39 per year in 2020-21 compared with 2017-18.
For those in Sunshine Coast and Noosa councils, it would be an increase of about $71.
In Redland City Council, it would be an increase of about $80.
Under option one, the common price would reset in 2018-19 and then increase by inflation, and all council areas would pay the common price in 2019-20.
Under option two, increases for all council areas would be smoothed over the three-year period and all council areas would pay the common price in 2020-21.
Quensland Competition Authority chairman Roy Green said the draft report recommending bulk water prices for south-east Queensland for 2018-21 had been presented to the state government.
"Under the first option, the current bulk water price for the eight councils paying the common price - Brisbane, Gold Coast, Ipswich, Lockyer Valley, Logan, Moreton Bay, Scenic Rim and Somerset - of $2.82 per kilolitre - would rise by 3.2 per cent in 2018-19 and 2.5 per cent in 2019-20," Professor Green said.
"Under the second option, the common price applying to the group of eight councils would rise by 2.8 per cent in each of the three years.
"A common price of $3.06 per kilolitre would apply to all 11 councils by 2020-21."
The second option would result in more gradual increases for Sunshine Coast, Noosa and Redland City councils over three years rather than two.
The Queensland government took over control of the bulk water supply from the region's councils in 2008.
To reduce the price impact of significant investments made in water infrastructure in response to low water availability, the government decided that bulk water price increases should be phased in over time.
To avoid an initial sharp price rise, prices were set to initially recover less than the cost of supplying bulk water, and gradually repay the deficit until 2028.
The QCA estimated Seqwater should be allowed to recover $8.1 billion in costs between 2018 and 2028.
The QCA completed its first full review of Seqwater's bulk water prices in 2015 and recommended prices until June 2018, with the Queensland government setting prices that were consistent with the recommendations.
People can comment on the draft report until January 31 at www.qca.org.au.