Bournemouth & West Hampshire Water (BWHW) provides clean drinking water to around half a million people in an area in the south-west of the UK spanning over 1000 square kilometres. This amounts to an average of about 150 million litres of drinking water every day, through nearly 3000 kilometres of water mains.
This is no mean feat. Not only is it a sizeable area, but BWHW’s large infrastructure is complex and aging: pipes laid in the Victorian era are still in service and a wide variety of materials — including cast iron, ductile iron, cement, PVC or plastic — is used for buried pipes, which have a diameter ranging from 50mm up to 900mm. At the same time, BWHW must manage the system in line with the stringent, risk-based, requirements set out by OFWAT (the regulator for the water and sewerage industry in England and Wales) to provide good quality service at a fair price for consumers.
A key challenge is pipe replacement, particularly in terms of identifying which sections should be a priority for renewal. Halcrow was commissioned to develop a risk-based model to consider and improve the capital efficiency of BWHW’s water distribution pipe network replacement programme. It did this using risk analysis software @RISK, in conjunction with its own ‘cluster’ analysis tool to combine the probability of pipe failures across the region with the consequential benefits of pipes not failing in the future.
The result is a risk analysis model that allows BWHW to make more informed decisions about targeting investment. From there the water company is able to replace pipes that, should they burst, would have the most significant impact on the level of service it offers its customers as well as the direct costs incurred by the organisation.
Taking a risk-based approach to its pipe replacement programme gives BWHW the assurance that it is achieving the best possible return on its investment. It is also ensures it can maintain its good record for providing good value and service to customers.
EMEA Managing Director of Risk & Decision Analysis