Freeze—thaw and the dry weather events in FY2022-23 have increased focus on investments made by the water industry in striving to reduce the risk of water supply interruptions and our ability to respond and recover. Minimising customer water supply interruptions is a priority, now. There is however a balance to be struck between short-term operational investment (including patch repairs, event management and alternative supply vehicles) alongside longer-term capital maintenance (including trunk main maintenance and renewal). There is great diversity across the sector in prioritisation and investment to achieve water supply interruption resilience and recovery. The sensitivity of performance to weather and other external factors shows there is still more to do for the sector.

We have a statutory planning framework for water sufficiency in Water Resources Management Plans as well as long-term planning requirements for Water Quality (submission of Long Term Water Quality Plans to DWI), but there is no consistent planning framework for optimising resilience to short-term water supply interruptions (WSI) and events.

The recent UKWIR BQ03-CO8 root-cause project confirmed that mains bursts are the primary contributor to WSI across the sector. Whilst there are multiple root causes for mains bursts, asset health deterioration is likely to be a significant contributor.

Water companies have invested heavily to improve response and recovery following mains bursts (and similar) whilst also investing in the renewal and replacement of water mains at a sustainable and affordable rate. The fundamental question that needs to be addressed is when are the benefits of short-term operational investments overtaken by the negative performance impact of asset health deterioration? This is particular pertinent for companies who utilise a network of larger diameter trunk mains which are traditionally far more challenging to maintain and renew than DMA level water mains and result in large scale WSIs in the event of a burst. Continued investment in response and recovery activities are crucial, but acceleration and increasing scales of capital maintenance investment beyond existing regulatory Botex cost model allocations will be required to meet future “demand” – but when? 

*in line with Ofwat’s expectations for annual renewal rates within existing Botex allocations

In order to effectively prioritise BQ3 Route Map research activities we need a clear understanding of the major root causes of failure leading to interruptions to supply (ITS) across the industry.  There is a need to assess if there are pipeline characteristics, environmental location and conditions, or third-party impacts that are main or high contributors to ITS events across the industry.  There is also currently a lack of consistent methods across the industry regarding root cause failure analysis (RCFA). Lack of awareness of this can trigger premature or incorrect capital investment where very expensive mains replacement may occur prior to all operational or maintenance mitigation being exhausted.

At present, there is no readily available national data on the relative property minutes contributions of ITS events on large diameter mains as opposed to smaller diameter mains or between material types. This relatively basic asset information alone could significantly inform or reaffirm industry and BQ3 route map research priorities moving forwards in terms of relative focus on trunk mains or distribution mains and certain material types etc.

By gathering and interpreting ITS root cause data and information across the industry, the BQ3 research programme can then be further prioritised to focus on those assets that have the greater risk of causing ITS events.  This project will also provide an agreed industry data protocol for future data collection in this area and enhance the effective specification of appropriate datasets for the development of the new National Failures Database (NFD), running as a parallel project. 

By focussing BQ3 research projects on those assets that are more likely to cause ITS events, we will ultimately reduce those events and move towards “Achieving zero interruptions to supply by 2050”.  This will not only provide a better service to our customers but encourage more efficient ways of working within water companies in this area, improve practice and ODI impact and, ultimately, reduce major incident risk.