Project overview
The Southern Strategic Support Main serves a dual purpose to the Bristol Water network. Primarily, it provides resilience to both the southern and northern supply zones, removing 280,000 people from risk of a single asset failure. Secondly, it helps to support the growth in the southern zone by providing an additional 22.5 Ml/d to this zone. The scheme addresses known risks including impact of drought events (resistance), increased demands, deterioration of water quality and algae blooms (reliability), power & asset failure (redundancy) and managing service failures (response and recovery).
Key project stats
Our role
Binnies developed and analysed a long list of over 30 different options to determine the optimum means of providing a resilient supply, considering a combination of pipeline, treatment, pumping and reservoir solutions. The resulting solution was a 30km long pipeline linking three water treatment works, providing mutual resilience and minimising pumping and reducing environmental impacts. We delivered the concept, outline and detailed design, environmental consultancy and construction support. Our multi-disciplinary, seconded team worked collaboratively with Bristol Water, suppliers and the supply chain to leverage innovation and efficiencies.
As Technical Authority we mapped out the process to ensure needs were validated and challenged across the scheme life cycle. The resulting tailored efficient solution reduced TOTEX by £4M by shortening pipe routes and deferring service reservoir construction. We drove adherence to the gateway process and achieved close interaction with operations, constructors and suppliers generating innovations, including fabrication of longer pipes reducing joints and deliveries by 15%.
The design team were involved in public consultation throughout the scheme; engaging with the public reduced design changes, which added to efficiency. The early and close working relationship with the contractor allowed constructability to be optimised, driving down costs, reducing environmental impact and allowing environmental enhancements to be incorporated.
- Centralised service reservoir from feasibility solution restricted pipeline options and increased operating costs
- Managing known risks including impact of drought events (resistance), increased demands, deterioration of water quality and algae blooms (reliability), power & asset failure (redundancy) and managing service failures (response and recovery)
- Very tight programme to meet Ofwat’s deadline and avoid penalties for the client, with only 3 years between start of optioneering and handover of the scheme
- Routing a pipeline across the Mendip Hills whilst minimising operating costs
- Complex surge analysis and GIS based routing optimisation enabled the service reservoir to be decentralised and enabled deferred service reservoir construction expenditure
- Enhanced collaboration including upstream land referencing and downstream data verification
- Protected the network to benefit future generations whilst improving biodiversity
- Routing the pipeline through a former railway tunnel beneath the Mendips: requiring innovative pipeline installation techniques; mitigation for protected species, and minimization of construction impacts on customers and the public