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Wollongong City Council

Hewitts Creek Catchment

The Hewitts Creek Catchment area covers an area of around eight square kilometres in Thirroul and Bulli.

Map of Hewitts Creek Catchment  PDF, 632.12 KB

The Northern Area Floodplain Committee provides advice to Council about issues in Hewitts Creek Catchment area.

A Flood Study, Floodplain Risk Management Study and Floodplain Risk Management Plan for this catchment were completed in 2002.  This was followed by a review of the Flood Study in 2015.

When Council’s Conduit Blockage Policy was updated in 2016, the Flood Study (2015) was revised to take into account this Policy and recent development in the area.  This revised Flood Study (2019) provides the most up-to-date information on flooding for the catchment, and supersedes the 2002 and 2015 Flood Studies.

The 2002 Floodplain Risk Management Study and Plan is currently being reviewed to take into account the outcomes of the revised Flood Study (2019).

The above completed studies can be found in the Documents section of this page.

All studies have been jointly funded by Council and the NSW Government.

Current Works and Projects

There are currently no works in this catchment

Planning matrix

We’ve added a matrix for the Hewitts Creek Catchment into Chapter E13 of the Wollongong Development Control Plan PDF, 1824.81 KB. This helps people understand flood risks when they’re planning new development in the area.

Black Diamond Place detention basin

We’ve modified the layout of the Slacky Flat detention basin at the eastern end of Black Diamond Place, Bulli. This included closing an old spillway and adding a making a new one to direct overflowing water away from Beacon Avenue and back into Slacky Creek.

The Esplanade overland flow path

We reshaped and lowered part of the open space between The Esplanade and Flanagans Creek in Thirroul. This helps overflowing water drain towards Flanagans Creek to reduce shallow flooding in the recreation area and nearby properties.

Lachlan Street culvert improvements

We’ve done improvement works on the culvert under the road at Lachlan Street, Thirroul. This was to reduce blockage from debris and reduce water flowing over the road and entering properties. Work included:

  • Adding gabion walls along both creek banks on the northern side of Lachlan Street
  • Adding a concrete apron and wingwalls on the upstream side of the culvert
  • Lowering the culvert headwall on the southern side of Lachlan Street
  • Adding a concrete wingwall on the downstream face of the culvert
  • Installing safety handrails and landscaping.

Corbett Avenue levee

We looked into creating a levee on the northern banks of Hewitts Creek in the Corbett Avenue / Hamilton Road area. However, the costs of the project outweighed the expected flood benefits, so this project is not going ahead.

Tramway Creek railway culvert

The area immediately upstream of the railway line embankment and Allenby Parade at Bulli is prone to flooding because the existing culvert is too small and easily blocked with debris.

We prepared a detailed design to upgrade the culvert so it could handle more water and be less likely to block. However construction work did not go ahead as the costs far outweighed the expected flood benefits.

Voluntary purchase

Three properties in this catchment were earmarked for a voluntary purchase scheme. We have bought and cleared two of those properties.

You can help our research and planning for floods in this catchment by sharing your past experiences.

If you have photos or other information about flooding on your property, please email us or post information to the mailing address in the footer of this page.

Hewitts Creek Catchment Study Documents 2019
Type Name File Size
PDF File Hewitts-Creek-Flood-Study-2019-volume-1-of-2.pdf 9.2 MB
PDF File Hewitts-Creek-Flood-Study-2019-volume-2-of-2.pdf 47.2 MB
Hewitts Creek Catchment Study Documents 2002
Type Name File Size
PDF File Hewitts-Creek-Flood-Risk-Precinct-Map-2002.pdf 221.6 KB
PDF File Hewitts-Creek-Floodplain-Risk-Management-Plan-2002.pdf 6.2 MB
PDF File Hewitts-Creek-Floodplain-Risk-Management-Study-and-Plan-Report-2002.pdf 15.6 MB