The Hidden Loo Problem Wasting 400 Litres a Day in Cornish Homes

Your toilet could be quietly pouring hundreds of litres of water down the drain every single day, and you would have no idea it was happening.

That is the warning from South West Water as it marks Water Saving Week, which runs from the 4th to the 8th of May 2026. The company is urging households across the region to carry out a simple check that takes just minutes but could save thousands of litres of water and money off metered bills.

The scale of the problem

Hidden toilet leaks are present in around 10% of UK households, and a single leaky loo can waste up to 400 litres of water a day. That is enough to fill a bath two or three times over.

Because the leaks are usually silent and invisible, most people never realise their toilet is the culprit. Around 30% of water loss in the South West Water region comes from customer pipework rather than the company’s own network.

How to check your toilet at home

South West Water is offering free leaky loo strips to customers. The biodegradable, water-soluble strip sticks to the inside of the toilet bowl and changes colour and dissolves if a leak is detected.

If you do not have a strip to hand, you can do a similar check with a few squares of toilet paper. Place them at the back of the toilet pan, under the seat rim, and wait around an hour after the last flush so the pan is dry. If the paper becomes wet, you have likely got a leak.

What the experts say

Megan Williams, Water Efficiency Manager at South West Water, said: “Our teams are working hard to reduce leakage across our networks and it’s really important that we support our customers in doing the same.

“Climate change is showing us that we all need to be mindful of the water we use all-year around, and by keeping our customers informed about household leaks they might not be aware of, we can help reduce demand, protect water supplies and deliver lasting benefits for communities and the environment across the region.”

Nicci Russell, CEO of Waterwise, the organisation behind Water Saving Week, said: “South West Water’s leaky loo campaign is so important. Leaky loos are one of the biggest water wasters in the home. Last summer was the UK’s hottest on record, and last spring was the driest in England in 100 years. There is no magic new water, and there are more people needing to use it every day.”

More information on free water-saving devices and tips for cutting water use at home and in the garden is available on the South West Water website.