Port Lincoln drainage system upgrade in the pipeline

A $3.2-million drainage system upgrade to the Liverpool Street and Eyre Street precinct will help mitigate the area’s flood risk.

Eyre and Liverpool streets have been prone to flooding; in late 2015 the area was inundated after heavy rainfall and again in early 2016 when parts of Liverpool Street were closed due to flooding.

At its meeting on Monday last week the Port Lincoln City Council considered three options identified in the Mortlock Terrace and Liverpool Street Flood Mitigation Study.

While the project cost is $2 million more than the anticipated $1-million project scope funded in the Long Term Financial Plan in 2018/2019, acting mayor Neville Starke said it would significantly improve the performance of the drainage system.

The council decided on the stormwater management option that would give the Liverpool Street and Eyre Street precinct a drainage system capable of managing a one-in-20-year flood event.

The new drainage system will also increase the pumping capacity to at least 1200 litres per second.

The existing pump, drainage and generator infrastructure performs at about a one-in-two-year standard, pumping 760 litres per second, resulting in a 40 per cent chance of flooding in any given year.

The upgrade will also give the council the ability to increase pumping capacity and implement complementary works next to the Liverpool Street catchment to improve drainage system performance.

Mr Starke said the council had to carefully weigh up the options and make a responsible decision to lessen the flood impact and manage the financial effects on the city’s ratepayers.

Mr Starke said the council would be seeking a 50 per cent subsidy from the Stormwater Management Authority.

“We can significantly reduce flooding impacts in sections of Liverpool Street by committing a major portion of our 10-year forward funding for stormwater works across the whole city.

“The overall program, now expected to be $7 million over 10 years, also needs to address other areas in Port Lincoln that have stormwater problems.”

The council’s Long Term Financial Plan includes more than $5 million in capital funding for drainage projects over a 10 year period, including the now $3.2 million works at Liverpool Street.