You may have noticed a lot of Thames Water vans around in the last few weeks, and people in Thames Water uniforms taking lots of photos of tiny drain covers in the pavement, as well as painting them white. As you’ve probably guessed from the title of this post – we’re about to have water meters rolled out to all the houses that don’t already have them, and if a small drain in front of your house has recently been painted white, you’re going to get one too.

Why? It’s all about reducing our use of water. Despite London’s international reputation as a wet & rainy place, South-east England actually has remarkably little rain, and is officially classed as “semi-arid” and more or less permanently water-stressed. The Environment Agency’s classification (below) identified it as an area of serious water stress.

Originally water meters were very much voluntary, but there was nonetheless a strong encouragement for people to volunteer to have one installed – mostly by gradually ramping up ‘unmetered’ tariff rates to make it cheaper for almost all households to have a water meter than not have one. That has changed now, as the region Thames Water covers is officially an “area of serious water stress”, meaning they can install meters on a rather more efficient basis – doing them street by street and covering all the remaining properties at the same time, rather than waiting for individual householders to contact them and ask for one.

The rollout has been underway for the last few weeks in the Wimbledon / Southfields area, and will eventually cover most of London and the surrounding areas – and by and large it’s the houses that have nothing outside but a rusted stop valve like the ones below that will be converted to new meters. You can expect a small hole to appear and then for a slightly larger drain to be fitted with the meter inside it (the white painting & photos are part of the process of getting Council permission to dig up specific parts of the pavement).

This will hopefully go some way to dealing with a predicted water shortage of around 387 million litres of water a day in the London area by 2045, which is expected to get worse with time increasing to 688 million litres of water a day by 2100 (a quarter of the water Thames Water currently supply!). The choice is either to ship a lot of water to London from the north at great expense (think huge pipelines, reservoirs and pumping stations), or to push out meters to get us to use it more efficiently. And it seems we all use less water when we’re billed for it by the cubic metre (Thames Water reckon water use goes down by twelve percent).

That said, there is another thing Thames Water can do: reduce the number of leaks in their ageing water network! In February this year they lost a staggering 732 million litres of water every day to leaks (which is rather more than the total predicted daily water shortfall in 2100). It’s a big and difficult job: in the same month they repaired 4,568 leaks, but realistically a lot of London’s pipework apart from the really major water mains is a creaking mess of lead and ancient cast iron and needs a major upgrade, and Thames Water have consistently missed their leak reduction targets. To be fair they are getting increasingly clever at finding the stealthiest underground leaks, using acoustic sensors that can detect the quiet hissing of an underground leak, and tiny underwater cameras, to pinpoint the exact location of a dodgy pipe and make them as quick to repair as possible.

There’s a twist too: Most of these new water meters will be cutting-edge ‘smart’ water meters, which take a reading every hour or so and can be read remotely. Thames Water is a pioneer in installing these, and a few weeks ago installed the 500,000th smart meter. These ensure accurate bills and avoid the need for meter readings, and can also detect steady leaks inside and outside houses (as they spot gradual steady water use). They’re quite clever in technical terms, as they need to work underground and sometimes underwater or covered in mud (as anyone who’s looked into a pavement meter drain can confirm, it’s often not pretty down there), as well as having their own power supply.

Smart meters can be a sensitive topic, and we know some would very much prefer not to have a water meter at all, let alone a smart one that generates date on their day to day water use. But rejecting a water meter is becoming an expensive choice, as Thames Water can apply a “no access charge” water rate to anyone who denied them access for the purpose of fitting, maintaining, replacing or reading a meter; which currently runs at over £600 a year (more than the assessed charge for a five bedroom house where someone asked for a meter but it wasn’t possible to fit one for technical reasons, and over three times the rate for a typical two bed flat).

Conversely – meters are a fairer way of charging, will make sure that water bills reflect actual usage, and may well lead to lower bills for many. They’re probably preferable to constructing new pipelines water treatment works and reservoirs across the countryside. A minor extra benefit is that the new meters include a small tap that can turn off the water supply in the property (all you need is a screwdriver to open the drain cover and long arms, or maybe a pair of pliers, to reach and turn the small tap) – which can be handy for anyone who has a big leak in the house and finds their mains water tap is jammed, or that it’s been buried somewhere behind the cupboards of a fitted kitchen (both quite common occurrences).

Either way – this is now set to happen – so we can expect to see a lot of pavement excavation in the near future.