Reservoirs aren't even half of the story

3rd August 2023

Where does water come from, how does water get to your taps and why does making the most of it matter? All water we use originally comes from the environment, from more sources than you probably realise.

Let’s start with reservoirs. Most people know reservoirs are a source of water, and when they’re full, you may think that’s OK, right? Not quite. They’re not the only source of water.

In fact, at South East Water, reservoirs only make up about 8% of where we get our water from. The rest comes from underground aquifers, boreholes, and chalk streams. Let’s come on to those in a moment.

These sources, which are called ‘raw water’, are only half story. So, what is the other half?

It's the water we use, or more importantly, how much of it we use, which we call water demand. It’s not just people who need these water sources. Trees, plants, crops, wildlife, livestock, fish, birds, and insects – indeed, all flora and fauna – depend on the same water to survive and thrive.

The more water we take, the less there is to go around for everything else. Producing more is not that simple because these precious sources of water need to be protected, and building infrastructure takes a long time.

The best way is to be mindful of water use, and there are lots of small ways to save water in the home and garden.

So, what exactly are aquifers, boreholes, and chalk streams?

Aquifers -

An aquifer is an underground body of rock or sediment that holds water.

Boreholes -

The water from aquifers can be extracted from the ground through boreholes by pumps, like a giant straw that enters aquifers and sucks the water out.

Chalk streams -

There are only around 200 chalk streams in the world, most of which are in the southern half of England (with a few in France), which makes them even more special.

These are rivers that rise from springs and have chalk bedrock. As the chalk is spongy, rainwater easily moves through the ground and to the chalk streams.

How does water get to your taps?

Once the raw water is collected, it’s put through a rigorous and highly regulated cleaning process. There are nine treatment procedures that make the water clean and safe enough to drink. Take a look at each step of the process here.

Once treated, the water is moved to storage reservoirs around the network and boosted through the 9,000 miles of pipes that connect to customers’ homes. Usually, it takes around two hours to treat and store water, so it’s ready to be used.

When the demand for water is high, the amount of treated water in the storage reservoirs drops, and in times of extreme demand, if more water is used than which we can replenish, some customers may experience low pressure or no water.

This is why making the most of every drop matters. Simple swaps in mindset, such as using a watering can and showering for one less minute, can save more water and money than you might think!

To do our bit in saving water, we spend £40 million a year managing and reducing leaks and have 52 leak repair teams and 60 leak detection experts using innovative technologies in our supply region.

We also continually invest in our infrastructure, where between 2020 and 2025, we're investing more than £489 million to develop new resources, extend and upgrade treatment works and lay new water mains.

It doesn’t stop there either, we have been working on our future plans, and you can find out all about those here:

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