Broome is to get a new, permanent wastewater pressure main to alleviate strain on the existing system, which is now close to design capacity.
Water Resources Minister Ernie Bridge said the Water Authority would spend $366,000 on the project this financial year and a further $61,000 in 1993-94.
He said the ongoing development of the area west of Port Drive made the work essential.
"The alternative would be restrictions on Broome's capacity to maintain economic growth," he said.
The final route of the pipeline was being determined in consultation with the Shire. While it was to have been along Gubinge Road through vacant Crown land and road reserves, this was now being re-examined because of uncertainty over the final alignment of Gubinge Road.
Mr Bridge said the Water Authority was also discussing with the Shire the possibility of re-using treated effluent from the treatment plant to provide additional water for landscaping in the town. The effluent could also be used on the golf course greens.