Pipes bursting with success
The Met Office, in association with Thames Water, recently launched a Œstate-of-the-art' weather forecasting service, designed to give advance warning of potential burst situations, particularly in underground cast iron pipes, when sub-zero temperatures are anticipated reports Brian Dumbleton.
"Cold weather bursts can be caused by a combination of factors such as ground movement, pressure variation, vibration and wear and tear. Really low temperatures lead to multiple bursts and as a result we have already received enquiries from engineers in Canada, the USA and Poland regarding our system," said Mr Tutton.
Using a computerised ground temperature depth model it combines site specific weather forecasts, sensitivity analysis and historical data to predict in particular unexpected bursts over and above traditional anticipated ones.
"Times of peak demand are the most vulnerable and we have determined that there is a significant time lag between prevailing and forecast weather conditions and actual serious bursts," said Anthony Astbury, business group operations manager at the Met Office.
"Following considerable tests and research, we have established a link between the ground temperature 0.3m below a road surface and bursts," said Mr Ashbury. 0.3m was determined as the most sensitive depth, but with more available data the system can operate down to a metre which is the depth of an average water main.
We have now installed over 700 Œroad sensors capable of producing the best data available of its kind in Britain. This information is then transferred into Œburst mode¹ enabling us to forecast much more than just the weather. "Because we can now look four days ahead, we neither over or under react so the potential benefits for London and other large conurbations are very considerable. The model does not pinpoint particular bursts in specified mains but is highly effective on an area basis and is aimed at reducing inconvenience for both consumers and road users," explained Mr Tutton.
The Met Office is also constantly looking at ways it can expand and develop its services. "For instance much of the information we supply to the water industry is now based on weather radar enabling us to provide an updated forecast every 15 minutes and we also operate a Œsewer flooding register' service and ŒMIST' a PC weather information system," said Astbury.
"This enables the latest data to be transmitted direct to operational control centres throughout the UK and is used to schedule maintenance and site access, co-ordinate fleet vehicle activity and monitor river flow and sewerage systems," explained Astbury. Severn Trent has also recently commissioned the Met Office to provide an assessment of climate changes likely to affect its operations. "Among other topics we are currently researching are changes in rainfall resulting from increased greenhouse gases to enable us to assess our urban storm water drainage systems," said Met Office senior account manager Alyson Bedford. "Climate change is likely to have a significant impact on our services and the way in which we operate. By working with the Met Office we can plan our needs efficiently and make any necessary changes to our services in good time," said Severn Trent's director of asset planning and investment Dr Terry Kitson.
This should be all good news for the Environment Agency which expects water companpies to over-achieve on the new mandatory leakage charges set by Ofwat for 1999/2000.
"We are of course glad to see any progress being made. Figures published to date represent the very minimum that companies should be expected to achieve," said EA's director of water management Dr Geoff Mance. "Their ambitions should and can extend to beyond these targets and they should continue to strive to maximise the benefits for their customers and the water resources available to them.
"We are also anxious to bring the debate about leakage levels into the open so that the assessments by water companies of their economic levels of leakage can be published and we can then examine and compare the assumptions and conclusions," said Dr Mance. "Meantime the Agency will continue to press for rapid progress with leakage control and will not issue any new water abstraction licences unless it is satisfied with the water company's performance in this critical area."
Also MVA, a multi-disciplinary consultancy, recently completed a contract for Thames Water designed to assess the traffic disruption associated with leakage control. Working in association with WRc, MVA was commissioned to evaluate the costs to motorists and other vehicle operators of road works to them, as a result of Thames Water's leakage control programme, estimated at around £1 million a year.
"Leakage control results in hidden costs arising from disruption to traffic
when roads are closed or particularly closed for leak detection and/or
repair," said MVA project leader Neil Shepherd.
"These are vitally important
when assessing the wider and longer-term impact of maintaining adequate
water supplies," he concluded.