Parkridge Boat Ramp
City of Mandurah
Overview
Westpeak Engineering recently designed an upgrade for the Parkridge Boat Ramp which is located on the Harvey Estuary and managed by the City of Mandurah. The existing boat ramp is around 20 years old and has deteriorated beyond repair. Furthermore, portions of the facility, including the fixed timber jetty sections, don’t meet the relevant current day Australian Standards and Department of Transport Guidelines.
Our services involved:
- Desktop study of relevant background information, including survey data and aerial imagery, to identify opportunities and constraints.
- Site inspection to measure and check the condition of various elements and capture an orthorectified aerial image of the facility.
- Engagement and management of a geotechnical consultant to undertake an investigation to assess and determine foundation and pile design parameters.
- Concept design and presentation to the City.
- Detailed design in accordance with the relevant Standards and Guidelines.
- Documentation suitable for Tender, including Drawings, a Technical Specification, a Safety in Design report and Price Schedules.
Project Highlights
One of the project highlights was incorporating the reuse of the existing northern floating jetty, steel piles and limestone rock into the upgrade. The northern floating jetty was constructed in a more recent extension (2016) and assessed onsite as being in good condition and suitable for reuse. The Technical Specification was also developed to accommodate the reuse of the existing steel piles and limestone rock. This is a great outcome for the project in terms of environmental impact and construction time/cost.
Project Challenges
- The limited depth of the Harvey Estuary waterway surrounding the facility.
- Scour and sedimentation potential due to the net transport of material from south to north along the relevant section of shoreline.
- A limited available footprint for the upgraded facility, despite the increased boat ramp and jetty width requirements in the latest Standards and Guidelines.
Project Solutions
- A practical boat ramp toe level and dredge depth was selected during the design process. This achieves a good balance between providing navigable depth for vessels using the facility and minimising dredge material (Acid Sulfate Soil) quantities and subsequent costs.
- Concrete access ramps were included at both northern and southern tie ins to provide access for a small excavator to undertake future bypassing works.
- Westpeak were able to reconfigure the facility upgrades to include a central floating jetty with launch and retrieval boat ramp lanes on either side. This meets the relevant Standards and Guidelines, reduces upgrade costs and has an overall footprint consistent with the existing facility, despite the wider ramps and jetty.
