Contribution
The hon. Gentleman is quite right that developers should pay their way. There is much to do, as I will come to.
On average, each house roof in England receives enough free rainwater to meet all its household’s non-potable—non-drinking—water needs, including flushing toilets, washing clothes and watering gardens. Instead of that, we send it, often at high speed, into the sewerage network where it discharges into our rivers. At the same time, we spend millions of pounds making pure drinking water, pumping it into our homes and flushing that down the toilet.
Around a quarter to a third of drinking water in our homes gets nowhere near being drunk. In fact, it is all flushed down the drain without a single drop quenching anybody’s thirst. It is an appalling and pointless waste of drinking water and energy. It means that we respond by investing tens of billions of pounds in reservoirs to hold a bit more rain, so we can treat more of it, pump more of it into our homes and—yes—flush more of it down the toilet unnecessarily. That is not environmental progress; that is a high-carbon and highly expensive way of papering over the cracks in our water system.
The water from our homes and highways—vast volumes of rainwater—continue to go straight down the drain as well, mixing with sewage, pointlessly being pumped and treated and pumped and treated, and far too often creating a backwash that sends sewage tumbling into the River Tone in my constituency and into rivers and beaches across the country.
Our waste water treatment plants can cope with the sewage that is produced. What they cannot cope with is the millions of litres of rainwater we add to the sewage before we send it to the waste water treatment plants. Too often we respond by investing huge amounts into storage tanks to hold stormwater, so we can pump and treat more of it. that is a high-carbon and highly expensive way of papering over the cracks in our water system.
The climate is making the problems worse and, ironically, our addition of rainwater into the mix is making the climate worse—a classic doom loop. As the atmosphere warms, England’s winters become wetter and our summers drier with more intensive thunderstorms. Meanwhile, housing delivery continues at scale, covering land with more impermeable surfaces while we continue to legally entitle developers to collect new rainwater and add that to the sewerage systems as well, which cannot cope. We are building the problem into existence before our eyes.
Contrast this with how we look and deal with energy. We no longer assume that all power has to be generated centrally. Instead, we actively encourage decentralised generation, such as solar panels on roofs which, thanks to my hon. Friend the Member for Cheltenham (Max Wilkinson), will now be required on every roof of every new home. We have batteries in homes and heat pumps replacing distant combustion, and we offer grants to make it happen. On water, we remain stubbornly stuck in—well, I was going to say the 20th century, but it feels like the 19th century.
Other countries have progressed. In parts of Belgium, new homes must capture rainwater for beneficial use. No wonder it has achieved the lowest per capita water consumption in Europe, and no doubt the lowest water bills with it. Australia, Germany and Singapore have embedded rainwater harvesting and source-controlled drainage into mainstream development. In England, by contrast, we continue to ignore rainwater’s massive asset value. Even the amendment I proposed to the Planning and Infrastructure Act 2025 that new homes should capture rainwater to use it and lower residents’ bills was rejected, I am sorry to say, by the Government.
This issue will not go away, and the alternative approach is really not that radical. It is all remarkably simple. The simple principle is what is called source control: capture rain where it falls, use it wisely and return the excess rain to the ground where it fell. Why use it to top up our sewage? Do we love sewage so much that we actually want to make more of it by adding more water and creating an even greater volume? For all those homes built in earlier centuries where rainwater is directed into the sewer already, why not offer grants to retro-split two drains from the one drain they have at the moment? It would mean lower costs for the consumer, lower water bills, less sewerage for water companies, less sewage going into our rivers and lower costs for the Government, the public and the agencies to cope with.
It could cut water bills by roughly a third, meaning £225 off the average household bill. A household in Taunton and Wellington that catches its own rainwater and takes it out of the sewer would cut its water bill by a quarter to a third. That is around £225 a year off a £695 bill. Nationally, that is 28% to 35% of the total bill. If we gross that up, that is £6.5 billion off bills across 29 million households. Imagine what that could do if it was freed up to be spent in the economy in other ways.