Drummond Modley and Martin Wood described the major project that Wessex Water has underway to improve and control the movement of water within its operating region. This project will take 8 years to complete and in the last three years it has cost £1M per week to implement.
The water industry in general was shown to be lacking resilience during the floods of 2007 and it was realised that Wessex Water was exposed to similar risks as its trunk distribution mains ran essentially East/West with limited ability to move water North/South. In addition there was pressure to reduce borehole extraction in the River Wyle catchment area, so as to improve river flow, and localised problems of high dissolved nitrate and iron levels, combined with increasing demand.
Several engineering solutions had been proposed, including inter-working with adjacent water supply divisions. Unfortunately from an engineering point of view the region is rich in areas of outstanding natural beauty, special scientific interest, historic significance and yet to be discovered archaeological artefacts. After taking all these matters into consideration a new North/South trunk main, to the west of the original proposal, was put forward as a business case and approved.
The project comprises 200km of main, 24 pumping stations and 12 storage tanks and will cost in total £230M. To ensure effective project management the scheme has been split up into simple programmes but visibility of the whole scheme has been maintained by using a networked project management tool available to all parties. This tool is mainly concerned with managing timetabling, resource management being limited to a few areas, such as the number of project managers required at any given time.
Some interesting techniques to mitigate risks to the project were described such as keeping the stages small and simple and trying to know as much about the potential work sites well before work started. By obtaining wider way-leaves than the main needed local deviations could be made if needed, say for archaeological reasons, without stopping the programme.
To control the new network and optimise program had been designed. It is currently being piloted in the Warminster area. The aim is to produce a water demand forecast for the next 72 hours at a 30 minute resolution. Its output will be a pump control schedule for the next 48 hours. The control rules are being developed, taking account of historic demand data, planned outages and variable electricity tariffs. Samples of water from the various parts of the network will be laboratory tested and used to determine the water movements required to keep nitrate levels below the limit.
It has been realised that the use of this software will change the operating culture of Wessex Water away from local control to a whole-system approach. This has meant developing a collaborative team approach, building on and maintaining local expertise and staff training.
The expectation is that the new supply grid and the optimiser will enable Wessex Water to meet a greater demand with greater resilience and yet use less water. To date the project is on time and within budget.
Water supply shares the characteristic of all the other utilities of 'just being there' – until they aren't. Quietly working away in the background. It was interesting to have revealed some of what is going on to keep us supplied. Massive though this project is, to most of us, it will be still largely invisible, which is an achievement in itself.
I am sure there are project management lessons here that could have application elsewhere. In particular trying to keep stages small and simple and to de-couple them from potential constraints. Personally I think one can take integration too far – we aren't that smart. I worked for a chief designer once who was an advocate for the 'big box', it left room to put in the bits that had been forgotten about and the need to re-design if there wasn't enough space.
For those of us more familiar with electricity supply there must be some envy for a system that can store its product yet perhaps relief and surprise that their product, unlike water, isn't perishable!
Project Focus: Optimising the Wessex Grid