Water stresshas just entered the urban-diagnostic-lexicon ("white flight" so last century, "nanny-cams" so last decade, "down market lifestyle drift"--that was a quick year): now, an inability to meet a city's water needs has stealthly shifted from distant arid nations to parched urban centers. Typical income and performance status-anxieties now seem quaint compared to "delivery system failure." Anxious Beijing, London and New York City utilities are scrambling to avoid water rationing by battling to stay just ahead of torrid population growth, antiquated water systems and reduced rainfall. Of the three cities, London was the first to throw serious money, resources, and new technology at the problem.
London's Victorian-era water pipes
Thames Water, the private utility operating London's water
supply, has been coping with a confluence of bad news. The city's population, a tsunami already topping 7.8 million, is expected to surge past 20 per cent over the next two decades.
London, commonly perceived as rainy, foggy and wet, is really much drier. The city gets half as much rainfall as Sydney, and even less than Rome and Dallas. A severe drought in 2005 and 2006 was a timely wake up call.
Purchased in 2006 by an investment consortium determined to make up for 20 years of chronic underinvestment, Thames Water is also sitting on top of a water system so old and complicated that many underground pipes can't even be found. Before they began an ongoing renovation four years ago, over half of the city's 10,000 miles of pipes were at least 100 years old--and frequently rupturing.
Repairing hundreds of daily leaks was as ineffective a stop-gap as hopelessly treading water. And the government complained that a quarter of the water paid for was being lost. Chagrined, Thames Water estimated the system was losing one billion gallons of water a day, achieving the dubious distinction of running one of the leakiest water systems in the modern world.
Replacing aging pipes
Targeting older pipes most likely to break, Thames Water has
worked hard to replace 1,300 miles of Victorian cast-iron water mains over the past five years. To accelerate the process and reduce neighborhood disruption, new plastic pipes are placed inside the old metal ones whenever possible. Although the new pipes are smaller, the smoother surface insures the same water flow. When they cannot insert a plastic pipe, the old pipe is completely replaced.
Racing the environmental clock, on any given day, work crews are digging up 300 streets around the city. The company has said that although it has been ahead of schedule, speeding up the program could bring the city to "gridlock." Vituperative blog posts from many already angry consumers confirms the company's concern:
Home Serve have been out and its nothing to do with our pipes, they took the tap off at our meter and we have no water coming at all so its a Thames Water problem.
And blast from another customer:
What a nightmare, hope they can get it sorted for you today.
Fortunately, leakage has already been reduced 25 percent to 750 million gallons a day.
Creating a smart network
Replacing Victorian era water pipes comes with a new approach to network management. Instead of relying on an aging SCADA (supervisory control and data acquisition) network that had frequently required the company to send out workers to take sensor readings and fix problems, the goal is "something more like a central nervous system." Thames water officials told The Economist:
...when the firm puts in new pipes, it also installs additional wireless sensors, giving it a better view of its network. "We can now tell where we have a broken main even before customers call us," says Bob Collington, its head of asset management.
Still in transition, this new equipment had given Thames a mixed legacy system. Operators in the central control center, monitoring precipitation and water levels from their computer consoles, can remotely control many of the system's valves and pumps.
...But if one of the pumps fails, they may still have to make a call: not all the valves can be remotely controlled.
In 2010 the network has begun to take on a new level of sensitivity. This year Thames Water is investing ?100m ($158m) so it can automate more of its processes.
If the project works, the system will not only automatically deal with leaks but also schedule work crews and send text messages to affected customers. Employees in the operations centre, explains Jerry White, the utility's head of operational control, will then spend less time monitoring the network and more on making the utility's processes more efficient.
Thames Water has also begun using a web-based service pioneered by TaKaDu, an Israeli startup company, to finally "see" what's happening in real time along its 10,000 mile network. Until now, most utilities have struggled to monitor their systems by using computer simulations based on hydraulic models. Most real time information was still unavailable or too voluminous to analyze.
The new software sucks up gallons of real-time data from existing SCADA water metering equipment (flow, pressure, quality and turbidity). It uses statistical algorithms to analyze readings of "sparse" and "spiky" data, which it then combines with weather, acoustic, and GIS data. The results enable operations center employees to easily identify small changes that precede bursts and other network malfunctions.
metering equipment (flow, pressure, quality and turbidity). It uses statistical algorithms to analyze readings of "sparse" and "spiky" data, which it then combines with weather, acoustic, and GIS data. The results enable operations center employees to easily identify small changes that precede bursts and other network malfunctions.
Network problems detected by TaKaDu ranged from normal leaks and bursts, invisible underground water leaks that had gone undetected for months and water theft from a fire hydrant used to fill a private pool.
Finally Thames has an easy way to analyze massive amounts of data. They have 60,000 parameters online every 10 minutes and with the TaKaDu software, every 10 minutes they can get updates and warnings. What TaKaDu is doing is turning the data into information the company can use to save water and money.
The desalination solution
A large reverse osmosis desalination plant, sporting a tidy bio-diesel footprint, has just opened in Beckton, East London. The 300 million dollar plant will supply additional drinking water to over 1 million people during drought and peak demand.
Water industry experts have also speculated that Thames Water could in the long-term connect the desalination plant directly to the next-door Beckton sewage plant, in east London, to produce recycled water. The recycling process uses similar technology and is usually cheaper than desalting water, but has so far been too unpopular to be accepted by homes anywhere in the world except the Namibian capital Windhoek.
Is there light at the end of the tunnel? Who knows? Apocalyptic or ameliorative? This Thames Water publicity photo unintentionally embodies future's ambiguity--mocking human limitations. Hopefully, ten or fifteen years from now, most of the water pipes will have been replaced and integrated with modern sensors. With constantly improving real-time water-flow software, backstopped by robust desalination, London might finally achieve water sustainability.
Photo: Man in sewer-- Thames Water Media
Photo: Replacing pipe -- Thames Water Media
Photo: London Sewer-- Thames Water Media
Photo: London buses-- Jon Bennet-- wikicommons
Photo: Dry lake bed: NOAA -- wikicommons
Photo: Water drop-- Jose Manuel Suarez-- wikicommons
- Thames Water and TaKaDu Recognized by the International Water Association for Practical Sustainable Urban Water Management (prweb.com)
- The Return of the River Thames (sierraclub.typepad.com)