Goldenfields Water has proposed investigating options for "treating, removing and minimising discoloured water issues" in the Mt Arthur scheme that includes the townships of Coolamon, Ganmain and Matong.

Goldfields Water said its three per cent increase in fees across the board would equate "to an average residential account increase of only $6 per quarter".

The water authority's draft 2019/20 operational plan, released for public comment this month, forecast nearly $23.4 million in revenue.

Goldenfields anticipated about $6.3 million in residential charges from Bland, Coolamon, Junee, Temora, and parts of Cootamundra-Gundagai, Hilltops and Narrandera council areas.

Goldenfields general manager Aaron Drenovski stated in the draft operational plan that the authority would make a "continued investment in the key assets required to deliver top-quality water"

Mr Drenovski stated that Goldenfields aimed for "growing our water supply system to meet the changing needs of our communities".

He also stated the authority had to make sure its plans were "are affordable and can be supported in a financially sustainable manner".

The authority will develop a 30-year plan for the treatment works and major pump stations in the Jugiong scheme, which currently accounts for 42 per cent of Goldenfields' total water production.

The draft operational plan aimed for a renewal of high voltage works and further investigation into future assets required at the Oura treatment plant.

The authority will raise its residential and high-volume user service fees with the starting 20 millimetre connection lifting from $194 to $200.

Residential charges for each kilolitre used will increase by 2.94 per cent.

The draft also proposed the to start design work for 40 kilometres of pipeline renewal between Temora and Ariah Park.

Goldenfields Water has invited public submissions on it draft operational plan until June 7.

The authority covers 22,500 square kilometres and more than 46,000 people between the Lachlan and Murrumbidgee rivers.