Project Scope & Technical Deliverables
This project involved undertaking technical assessments of existing concept designs and flood modelling, including the development of simplified hydraulic modelling tools (using software such as HEC-RAS, SSA and TUFLOW) to inform optioneering and verification of design solutions, scoping and undertaking geotechnical site investigations, and completing Concept and Tender Designs for a 4m3/s stormwater pump station, and interceptor pipe network comprising of 750-1500mm diameter pipes with inlet capacities exceeding 7m3/s.
As the lead consultant, Weir has provided all civil and hydraulic engineering deliverables for this project while coordinating and managing deliverables with a broader team of multi-disciplinary specialist consultants spanning geotechnical, structural, and mechanical engineering to electrical and controls.
Programme & Collaborative Approach
Being a Central Government-funded project, the physical works for the pump station needed completion by the end of June 2025. Given these very tight timeframes, our team, led by Navin Weeraratne and Bede Murray, established a strong collaborative approach with WDC’s project manager and other technical staff to complete the preliminary technical assessments.
An assessment of potential pumping options was completed within four weeks of appointment (noting the significant lead time required for pumps of this scale), with a performance specification for pump procurement completed and issued within six weeks of appointment alongside a Concept Design report.
Construction Support
This included the development of several analytical tools to inform the design process, including a 1D network model for assessing and sizing the interceptor pipes and pump station (using Autodesk’s SSA software), and a 2D overland flow path model (using TUFLOW software).
The 2D model was built to quantify the time of concentration and peak flows generated by short-duration storm events in the upstream catchments of Morningside Road (noting the requirement to size the inlet structures for the interceptor pipes accurately).
Site investigations spanning service location, survey and geotechnical investigations were scoped and implemented, with Tender Design, alongside an Engineer’s Estimate, completed and issued with relevant tender documentation including project specifications, schedules of quantities and a basis of payment in mid-November (i.e., within 15 weeks of appointment).
Since then, our team has worked alongside WDC’s project manager to procure the construction contractor and is now providing site observation and contract administration services to WDC.
