Marshalls Creek floodplain

Marshalls Creek is situated to the north of Brunswick Heads and has a long history of flooding, with a major flood event occurring recently in June 2005. Flood behaviour in this area is complex due to the multitude of creeks and hydraulic connections between major floodplains, including the Mooball Creek catchment in Tweed Shire and the Yelgun and Marshalls Creek catchments in Byron Shire. Both Councils therefore jointly completed a flood study in 2009 which covers the Cudgen, Cudgera, Mooball, Yelgun and Marshalls Creeks.

The Marshalls Creek catchment is the southern most catchment in this study and it covers an area of approximately 4200 hectares. Marshalls Creek flows into the Brunswick River approximately 1.2km from the mouth.

Marshalls catchment is linked to the Yelgun catchment at North Ocean Shores. There are culverts underneath Kallaroo Circuit linking the catchments. The catchment is bisected in a north-south direction by the Pacific Highway and the railway line.

Upstream of the Pacific Highway the catchment is predominantly agricultural and forested land. The area downstream of the Pacific Highway is significantly developed and this part of the catchment is a mixture of urban (including golf course) and forested areas. Townships within the Marshalls Creek catchment include Billinudgel, South Golden Beach, New Brighton and Ocean Shores.

Depending on the relative flood levels, flow between Mooball Creek and Marshalls Creek occurs in both directions and can change during a single flood event. Lacks Creek and Marshalls Creek converge upstream of Billinudgel. The floodplain significantly increases in size at the confluence of the creeks. The flow is then constrained by the railway line before passing through the Pacific Highway bridges. Downstream of the Pacific Highway the floodplain is also large, with water backing up into the Golf Course area.

Other significant flood events occurred in May 1987 (this event is often referred to as “the Mothers Day Flood”) and March 1974. A smaller event also occurred in January 2008.

Documents

A previous Marshalls Creek Flood Study was finalised in November 1986.

The next phase for Council is to prepare the North Byron Flood Risk Management Study and Plan. The North Byron Flood Study will be used for the preparation of this document.  Until such time as the North Byron Flood Risk Management Study and Plan is adopted, the North Byron Flood Study (2016) and the Marshalls Creek Floodplain Management Plan (1997) should be considered for any flood planning matters.