A dripping tap is irritating for anyone, but when your day job is capital delivery director for major infrastructure projects at Thames Water, it takes on a whole different meaning, says Francis Paonessa.

This is why I'll never look at a leaking tap in quite the same way again. The tap in the kitchen recently started to leak and I’ll admit, my first thought was how incredibly annoying the “drip, drip, drip” was as I ate my breakfast.

It wasn’t the cost of the water, or how scarce a resource it is, because it was only a little leak, right? Well, wrong!

When I measured the leak (yes, I really did 🙄) I was amazed to find that these little drips added up to almost five litres a day. And that’s a staggering 1.7 tonnes of water over the course of the year - more than the weight of my car!

But here’s the dilemma, that water would only cost me about £4 on my bill over the year and the replacement valve fitting was £15 - unfortunately it’s a ceramic quarter-turn valve, not just a rubber washer. At an economic level, it’s just not cost effective in the short-term to replace the valve to stop the leak.

And the same is true on the 32,000km of the Thames Water network. The cost of fixing leaks massively outweighs the cost of producing the lost water, so one could take a short-term view and not fix the leaks.

However, this would create two problems. Firstly, little leaks have a nasty habit of becoming big leaks, and secondly, water is becoming an ever-scarcer resource, especially around London, so we can’t afford to waste it.

Our customers really care about leakage too – they see us wasting water in this way and it undermines our attempts to support them in using water more efficiently. The challenge is exacerbated by the fact that less than a quarter of the leaks on our network are visible on the surface, so we must employ a wide range of techniques to find them.

Over the past year, our teams have found and fixed over 60,000 leaks, which saved an average of more than 350 million litres of water per day.

Tens and tens of millions of pounds spent to save less than the £20k a day it costs to produce the lost water. But it’s absolutely the right thing to do for our customers and the environment and we are totally committed to make the investments needed to reduce leakage on our network.

So please do your bit to help too and fix those leaky taps - hopefully with a new rubber washer costing just a few pence. And yes, before you ask, I did fix the tap in my kitchen.