Water Saving Week 4-8 May: Ten Things to Know About Cornish Tap Water

Most people assume a leak is the water company’s problem. The numbers tell a different story.

This week marks Water Saving Week 2026, running from the 4th to the 8th of May, and South West Water is using the moment to share ten things customers might not know about what comes out of their taps. Some are surprising, others a useful reminder that the water arriving in Cornish homes has travelled a longer and more carefully managed journey than most of us think about.

1. Much of it starts as rain on the moors

A large amount of the South West’s drinking water begins as rainfall on Dartmoor, Exmoor and Bodmin Moor. These upland areas have little development or industry, which helps keep the water cleaner before it reaches the rivers and reservoirs. Rain runs over the land, into streams and rivers, and eventually collects in reservoirs.

2. Every drop is treated before you drink it

Before water reaches homes and businesses, it is treated at specialist water treatment works. The process removes particles, manages naturally occurring substances and kills harmful germs. It may sound simple, but it is tightly controlled and designed to meet some of the strictest drinking water standards in the world.

3. Your tap water is tested again and again

Water quality checks don’t stop once treatment is finished. Samples are taken regularly from treatment works, storage tanks, pipes and even customer taps. The tests are carried out by trained scientists, supported by laboratories, to make sure water stays safe all the way to the home.

4. Tap water is closely regulated

Drinking water in England is among the safest in the world. It is independently regulated and must meet strict legal standards, with results reported regularly and checked to make sure companies are meeting their responsibilities. In some countries, people still have to boil their water before they can drink it.

5. The way water is treated changes with the weather

The weather has a bigger impact on water than many people realise. Heavy rain can wash soil, fertiliser, animal waste and debris from roads, fields and towns into rivers and streams, and dry spells can change water chemistry. Treatment works are constantly adjusted, with operators fine-tuning the process every day to make sure quality stays consistent whatever the season.

6. Water is part of a continuous cycle

Water doesn’t disappear after it goes down the plughole. It is collected through the sewer network and cleaned at wastewater treatment works before being safely returned to the environment.

7. It doesn’t all come from reservoirs

Reservoirs are important, but drinking water in the South West also comes from rivers and underground sources known as aquifers. Around 10% comes from groundwater, with rivers and reservoirs each making up roughly half of the remaining supply on average. In wetter years more river water is used, but in drier years there is less available, so reservoir storage carries more of the load.

8. Summer tourism puts extra pressure on supplies

Cornwall and the wider South West is a popular holiday destination, and the summer months bring a huge jump in population in many areas. That means much higher demand at certain times of year, with careful planning, extra storage and constant monitoring needed to make sure there is enough water for residents and visitors during busy periods.

9. Around 30% of leakage comes from customer-owned pipes

South West Water says it has increased boots on the ground to find and repair more leaks than before, supported by digital tools and fixed network loggers, with plans to halve leakage levels by 2050.

What many customers don’t realise is that around 30% of leakage is from pipes that customers themselves own. There are simple ways to check for leaks at home, and for households on a meter a repair can mean a noticeable drop in bills. South West Water has guidance on spotting and reporting leaks on its website.

10. Water is a precious resource

Much of what customers pay for goes on work most people never see, including protecting water sources, maintaining pipes, testing quality and responding when things go wrong. By 2050, average daily water usage will need to fall from 145 litres to 110 litres per person, driven by climate change and population growth. For metered households, using less also means lower bills, and cutting hot water use brings energy costs down too.

More information on saving water at home and in the garden, including free water-saving devices, is available on the South West Water website.