Anglian Water is geographically the largest water and waste water company in England and Wales, covering 27 500 square km – around a fifth of England and Wales. Operating in the driest region of Britain, with just 600 mm of rain in a year, Anglian Water delivers more than one billion litres of water per day through its network of 36 000 km of water mains. It serves 2.6 million properties, supplying drinking water to 4.2 million people and waste water services to 5.5 million people across East Anglia and the East Midlands. Achieving top marks in all areas of 7 out of 17 categories, in 2008 Anglian Water was the best performing UK water company for the second year running.
If a water company is unable to maintain the supply of water in a crisis situation, Defra (Department for Environment, Food and Rural Affairs®) regulations under the Security and Emergency Measures Direction 1998 stipulate that an alternative supply of 10 litres per head per day must be provided by means of either bottled water or mobile tanks known as bowsers – or a combination of both. Failure to do this would be a breach of its operating licence, with the potential for public criticism and prosecution. In addition, bowsers must be positioned in public places that are safe and easily accessible.
When a water main bursts or the water supply is contaminated to the point that the supply has to be cut off, the bowser location procedure was previously to print off local maps, manually count properties, draw around each area of approximately 250 households and decide where to place one or more bowsers. If an incident interrupted the water supply to several hundred or even many thousands of properties, this operation could take a team of people several hours.
Fortunately, crises are not that frequent. Anglian Water’s outbreak of cryptosporidium in the summer of 2008 led only to ‘boil notices’. However, it did affect 250 000 people. Had the situation progressed to the stage where there was a failure to supply water suitable for drinking, cooking or preparing food, then Anglian Water would have been faced with the huge task of planning and executing the location of some 1 000 bowsers.
Preparing for such emergencies is the remit of the Business Continuity and Emergency Response Team for Anglian Water, and the response to an emergency is coordinated from the Operational Management Centre Incident Room in Lincoln. Caroline Wakelin is an Emergency Planner in this team and, as such, attended a workshop on geo-technology with a colleague. ‘We began to realise that there were capabilities that could be really useful to us and we could see the potential for automated bowser deployment.’ Caroline began talking with members of Anglian Water’s small GIS department: Paul Gomez, Information Development Manager for Geographic Information and Alaric Parsons, GIS Analyst.
There are 1.9 million postal properties within Anglian Water’s delivery area, and its GIS experts were already using OS MasterMap with Address Layer 2 (AL2) for topography and property address datasets within various core company systems. Team members use Intergraph’s vector-based GIS application GeoMedia, which defines features as lines, points and polygons. One of the team began by writing an application within GeoMedia to look at generating grids based on cells containing approximately 250 individual properties. Alaric Parsons explains, ‘Because of the density of population in urban areas, the cells would be small and closely packed, and in rural areas the cells would be larger and more spaced out. Inspecting the resultant grids would have helped us to roughly determine groupings of 250 households, but it would have been too slow and too time consuming in a real crisis situation.’
Looking for a solution to this problem, Anglian Water purchased an add-on application for GeoMedia that used raster technology to look at complete surfaces. In addition, in consultation with Intergraph, Canada, a highly innovative approach was developed to modify a density analysis tool. This takes the postal and MOWPA (Multi-occupancies without a postal address) features of AL2 and rasterises these points into an Intergraph programme, which finds clusters of 250 points that identify domestic properties, selects the centre points of these clusters, connects them with lines to their nearest neighbours and grows individual polygons outward from each centre point. Once the boundary of one polygon touches that of an adjacent polygon, they each stop expanding.
‘The areas within these polygons contain up to 250 points as designated by AL2,’ comments Alaric Parsons. ‘We know that we are capturing approximately 250 households, though some of these points will be classed as non-dwellings. We are therefore providing a guide, and in the event of an incident the emergency operations team can use AL2 to obtain a more comprehensive assessment of the number and type of customers at street level. They will, for example, be able to identify shopping centres and office buildings, and may decide to locate extra bowsers in certain areas.
‘Once we’d created the polygons, we could consider deployment locations,’ said Alaric. ‘We place bowsers in public spaces, so there is no postal address and we cannot pick out a postal point.’ The answer lay in the ‘Objects without a postal address (OWPAs)’ data, in effect a list of landscape features held within AL2. ‘Car parks, for example, do not have postal addresses, so AL2, which provides coordinates, is very helpful.’ Using this, Caroline arrived at a list of potential locations and attached a numerical priority to each one. ‘Ordnance Survey helped by advising on the contents of AL2 and the data classifications.’
From a series of queries Alaric created a set of preferred points and created a bowser deployment location database. ‘In rural areas there is little choice of landmarks, so we had to choose a centre point for bowser deployment. The GIS solution, which is capable of batch plotting, examines each polygon and generates a preview plot. We can add OS MasterMap Topography Layer background, give each bowser a polygon and attach all the details of potential locations.’
The solution is mounted on a stand-alone PC in Lincoln, so will continue to function should the network ever fail. The incident team can use the free-of-charge GeoMedia Viewer to see the Anglian Water Statutory Boundary, examine it with zooming and panning tools and then the background mapping of various scales will guide a user to the affected area. As the user zooms in further, the Statutory Boundary disappears and the District Metering Area (DMA) boundaries appear along with more detailed mapping, which shows the bowser deployment polygons and the preferred deployment locations.
When the user has zoomed in enough, the raster background disappears and the bowser polygon number labels appear. At this point the user applies a spatial filter to reveal the highest-detailed OS MasterMap background data and can then concentrate on one or more deployment polygons to determine the bowser location. With a polygon selected, it is possible to see exactly how many individual points are within that area, view their attributes, see the range of possible bowser locations and identify various boundaries. Alaric Parsons adds: ‘AL2 builds on earlier ADDRESS-POINT® products, which just had postal features; now we have much greater flexibility. Previously, we would have had to manually place a point for a non-addressable feature, now we have predefined points.’
‘It’s fantastic,’ says Caroline Wakelin. ‘It saves so much time. In the past three years we have actually deployed bowsers twice and prepared for possible deployment three times. The old process was extremely long-winded. We had to get out large maps, use highlighter pens, create spreadsheets and then email the information through to colleagues in the field. We had an incident in Scunthorpe where we needed to deploy just 12 bowsers. It took two people six hours to produce a definitive list of locations. The new procedure is so quick, easy and flexible that one person could complete a similar task within one hour.’
‘We knew that the other system was unwieldy,’ says Paul Gomez. ‘We have 8 000 bowser polygons on hard-copy, colour maps for our region and it’s difficult to negotiate that many pieces of paper.’ Paul Gomez continues, ‘In the event of an emergency, bowser drivers are often waiting for instructions. Any time a bowser is on the road and not dispensing water, we have a potential public health risk. We now have a clear primary choice of deployment location and alternative options. This is a key system.’
Return on investment
‘Whilst we work on the basis of one bowser to 250 households in conjunction with the deployment of bottled water to our vulnerable and priority customers, the Government is considering doubling the minimum provision of 10 litres of water per person per day to 20 litres per person per day,’ states Caroline Wakelin. ‘We are audited by DEFRA annually and the worst-case scenario is that we face prosecution if we fail to deliver. This solution prevents any potential problems and is easily adaptable to meet any new regulation.’
‘The government has set a requirement and any failure on our part or complaint from the public would be extremely damaging to Anglian Water,’ comments Alaric Parsons. ‘By enabling us to meet and exceed the guidelines, AL2 is helping us to safeguard our reputation.’
‘We want to maintain our number one position in service and efficiency and do all we can to maintain our position as a leading-edge organisation,’ states Paul Gomez. ‘For example, we will now update our 8 000 polygons each year because we are in a high growth area, even though we are only required to do this once every two years. Our work on this project underlines that commitment. Surface analysis is a niche application and we believe we are the first in the UK water industry to use this technology. We know of no other solution that can automatically locate points and find addresses. This project not only represents how we are using GIS to support the company, it demonstrates Anglian Water’s innovation and supports our work for PR 09, our next periodic review.’