Newell Highway Flood Immunity West Wyalong to Forbes


Transport for NSW

Project value





Marsden, NSW



In September 2016, the West Wyalong to Forbes section of the Newell Highway corridor experienced a 43-day closure due to heavy rain and flooding of Bland Creek and within the wider Lachlan Catchment. About 20km of the Newell Highway flooded between West Wyalong and Forbes in 2016.

The Bland Creek system at Marsden between West Wyalong and Forbes is a series of causeways and is usually the first part of the Newell Highway cut during large widespread events. The Bland Creek system flows into the Lachlan River System. In total flood water crossed the Newell Highway at seventeen locations between Compton Road, West Wyalong and Hereford Street, Forbes. The length of these flooded sections varied from 0.16km to 4.5km, while the depth of the flood crossings varied from 100mm to 800mm depending on the topography.

In March 2019, the Coalition Government announced it would spend $200 million flood proofing the Newell Highway between Forbes and West Wyalong.

The objectives of the project were to design options to achieve a trafficable road network between West Wyalong to Forbes that achieved a minimum flood passable level of service for an equivalent 2016 flood event; a minimum flood immunity of 1 in 20 ARI; and assess and value manage options for flood immunity passable for up to a 1 in 50 flood event.

What we delivered

Bellwether functioned as the constructability advisor and workshop facilitator.

Our team facilitated the Health and Safety in Design (HSiD) Workshop and the Risk Management Workshops.


Key outcomes

We provided certainty on the constructability of this project though our reviews of the program & methodologies and our risk inputs during HSiD phases.

Blythe River Bridge Strengthening
North Brisbane Bikeway – Chalk Street to Price Street
Captain Cook Highway Smithfield Bypass
Tinaroo Falls Dam Raising
Nullinga Dam Detailed Business Case
Stony Creek & Lindenow Options
Warrego Highway / Mt Crosby Road Interchange Upgrade
Fairbairn Dam
Maturing the Infrastructure Pipeline Program (MIPP)
Land Street Bikeway Underpass Duplication
Morayfield Indoor Sports and Events Centre Expansion
Torbanlea – Pialba Road Floodway Replacements Business Case
Samford Road Options Analysis
Logan Motorway East Bound Drainage Improvements and Pavement Rehabilitation
Gold Coast Tourism Hub Project – Bundall Road Site
Greenbank Transport Corridor
South Burnett Regional Council Systems Review
Cannon Hill Shopping Centre Bus Facility – Bus Station Upgrade
Newell Highway Flood Immunity West Wyalong to Forbes
Mareeba-Dimbulah Road Widening and Roadside Safety Improvements
Calliope River Bridge and Anabranch Bridge: Engineering Analysis and Options Analysis
North Pine Hub Strategic Assessment
Gregory Highway 27B – LN1 Culverts Upgrade Planning (Business Case)
Barwon Heads Road, Black Rock Road and Staceys Road Roundabout
Juliet Street Pavement Rehabilitation
NDRRA Flood Betterment Works – Merivale Street, Depot & Pidgeon Roads
Mackay Bus Stop DDA Compliance Program
Milton Street & Archibald Street Intersection Upgrade
Warland Street Drainage
Creek & Pipe Protection Works, Sunnybank
South Street & Burton Street Intersection
Whittle Street Drainage Upgrade
Capella Landfill Rehabilitation and Transfer Station Relocation Work
Springsure Landfill Rehabilitation
Leans Creek Bridge & Richardsons Bridge Repairs
Charleville Industrial Estate Stage 2
Caping Road Bridge
Virginia Park N’ Ride Upgrade
Gin Gin Streetscape Stage Two
Black Mountain Road Safety Improvements
Australian Department of Defence – Enoggera Barracks
Arrow Energy Dalby – Laydown Yard Upgrade
Toowoomba Waste Transfer Facilities
Pacific Highway Upgrade – Woolgoolga to Ballina
Easing Sydney’s Congestion – Pinch Point Program
Burdekin Falls Dam Improvement and Raising
M6 Early Works Construction
Warragamba Dam Expert Witness Report
South Batemans Bay Link Road
Gunns Gully Road Interchange
M1 Princes Motorway Improvements
Circular Quay Precinct Renewal
Wynnum Road Corridor Upgrade
Brookside Shopping Centre – Embankment Stabilisation