A Guide to Water Meters

Of all the utilities that homes and businesses use, none is more important than your water supply. The amount that we pay to use it is one expense that we have no way of getting around, and water meters are the means by which our use is recorded. 

While water shouldn’t be in short supply on this planet, the treatment that it requires and the costs of maintaining a regular supply to the standard that we accept make it an expensive infrastructural investment, and one which comes at an environmental cost. This means that we should try to not use it excessively. Water conservation is important. Water meters can help with this.  

What is a Water Meter?

A water meter is a device that records the water use at a given property. Your water supplier uses those readings to determine how much water you’ve used, and therefore how much you should be paying. Newer ‘smart’ meters can send these recordings directly back to them, without the need for a manual read.

How Does a Water Meter Work?

In the UK, water suppliers use two common billing methods: metered and unmetered. Generally speaking, only properties with a metered water rate either have or require a water meter installation, although some exceptions exist. Unlike electricity and gas meters, not every property is equipped with a water meter, so you might not even have one!

Benefits of Having a Water Meter

There are two main benefits to having a water meter, but they aren’t the only ones. The cost savings potential can be huge, particularly if you are a low-usage consumer. Water meters ensure that you’re only charged for what you use. This is both fairer and more accurate, which is important, given that water comes at an environmental cost. 

If you lose less water and are only charged for the water you use, your costs could shrink considerably. They may also help with the early detection of what could turn out to be troublesome and expensive leaks, and if you find that having one isn’t for you, you can change back, so long as it’s within two years. 

What are the Disadvantages of Having a Water Meter?

The biggest downside to having a water meter is the inverse of the biggest upside. Larger volume users could end up paying significantly more if they’re on a metered rate. For some businesses, this could get unexpectedly expensive. It’s also fair to say that, for residential users, not having one has been shown to devalue their property value.  

There have also been some concerns over the data they collect, and while they should always provide accurate readings, they require a stable internet connection and have been known to have technical issues in the past. 

Types of Water Meters

There are two main types of water meters; positive displacement meters and velocity-based meters. 

Positive Displacement Water Meters

Displacement water meters, often called Positive Displacement (PD) meters, are the most common water meters for residential and small commercial properties. They're great for measuring small volumes of water at low flow rates.

They contain mechanical parts (an oscillating piston or nutating disk) that are displaced, or moved, as water flows through the meter's main chamber. These moving parts measure the volume of water and increase the reading on your meter's register by the appropriate amount. 

Velocity Meters

Velocity meters have a blade rotated by water jets that turns at a known speed, and an internal strainer to prevent it from clogging. This type of meter is effective at low water flow and small diameters.

• Velocity Meters measure the speed at which the water moves through the meter's known volume. These are further divided into four categories:

• Electromagnetic and Ultrasonic Meters use magnetic fields or sound waves to measure water flow.

• Single and Multiple-Jet Water Meters use an impeller and rotation speed to determine water flow.

• Turbine Water Meters use a turbine to measure water flow.

• Compound water meters are used to accurately capture measurements where rapid and wide fluctuations in water demands are present. With compound water meters, you take two sets of meter readings. There is a larger meter for high flow and a second, smaller meter, for low flow. These readings are added together, and the customer is then billed for the combined usage.

Each has its advantages and disadvantages. PD meters are good at providing accurate measurements but also have some moving parts, meaning there will be some maintenance work required, and they can be prone to clogging. 

Velocity water meters offer advantages such as simplicity, reliability, and suitability for various flow rates. However, they may have limitations in measuring fluids with suspended solids or low conductivity. In recent years, with advancements in technology, electronic and smart meters that use different principles, such as ultrasonic and electromagnetic measurements, have gained popularity due to their accuracy and ability to provide real-time data for monitoring and analysis.

It is important that you understand how these meters work before you go ahead and order one particular type. What are your usage needs? What type of water do you want to measure, and where do you want the meter located? For many businesses, installation comes at a cost, so it’s important to know your budget, you’ll also need to take into account where you want it located and how accurate you need it to be.  

What is a Smart Water Meter?

Smart water meters are devices that measure and communicate water usage from consumer to provider in order to facilitate water management and proper billing. These meters are equipped with an electronic computing unit, or ECU, that facilitates communication between the meter and the supplier. 

It is worth remembering that the only substantial difference between a smart water meter and a normal one is that they deliver the information to the water supplier. The technology behind how they obtain that measurement broadly remains the same. 

Where is my Water Meter?

It is very important to be aware of your water meter location and to know how to read it. You can read the meter to check for leaks, submit your own reading in case of an estimated bill, and monitor water usage. You can employ water conservation methods to reduce consumption for better water management in your property.

Water meters can be located internally or externally. Internal meters can be found under a kitchen sink, in an airing cupboard or in a bathroom, usually behind a toilet; in businesses, they may be found in a boiler room or similar. External meters can be found immediately outside the boundary of the property that they serve, in the ground in a chamber with a lid. If you’re unable to find it, contact your water supplier and they may be able to help. 

How to Read a Water Meter - Understanding Water Meter Readings

Typically, meters use a standard unit of measure for volume, such as cubic metres or litres, recording the cumulative amount of water that has passed through them. If your meter is outside your property, you'll need to carefully lift the cover to access it. Your meter won't have a cover if it is inside your home. Some outside meters have a foam or polystyrene disc under the cover to protect your meter from frost. If you have one, make sure you put the foam back when you've finished. 

Check the serial number on the front of your meter matches the serial number on your bill to make sure you're reading the right meter. If they don't match, contact your water supplier.  Most meters have black and red numbers. You'll only need to give the numbers in black when you take a reading. If you have a digital internal meter, you'll only need to note the numbers before the decimal point.

To interpret your own readings, record every one, and subtract the old reading from the new reading to determine the amount of water used since the previous read. This will allow you to monitor your water usage. Remember to carry out regular reads for greater accuracy.  

How Often Are Water Meter Readings Taken?

If you have a water meter, it should be read at least once a year, and read by your water company at least once every two years. Some water companies might read your meter more frequently. Often the water meter is installed so that your company can read the meter remotely.

What Happens if I Don’t Have a Water Meter?

If you do not have a meter you will be charged a fixed amount each year ('unmetered' charges). These charges usually relate to the rateable value of your property. You should check your bill regularly to see how you pay for your water.

Are Smart Meters Compulsory for Businesses?

The government requires that smart meters are offered by energy suppliers to all small businesses and homes, but smart meters are not a legal requirement, therefore it’s not compulsory to have a smart meter installed.

How Do I Get a Smart Water Meter for My Business?

If you do not have a water meter at your property you can contact your water wholesaler to request a meter installation for your business. Unlike residential properties, this will usually come at a cost and this will vary depending on a number of factors. 

The majority of businesses are not in a business water contract, so may be paying a higher rate than they need to be for their business water and wastewater usage.

Can You Refuse to Use a Water Meter?

While in theory meters aren't compulsory, a water company can insist you have one installed if you fall into one of a number of different groups:

• Use an automatic watering device (such as a garden sprinkler)

• Automatically fill a swimming pool or pond

• Have a large bath

• Use a reverse osmosis softening unit

• Have a power shower

• Are the new occupier of a property (provided an unmetered bill has not already been sent to that occupier)

• Live in an area which has been determined by the Secretary of State to be an area of serious water stress and subject to a metering programme as part of a plan to maintain secure water supplies.

In 2007, the Environment Agency classed some areas of the country as being "water stressed”. These nine areas are the central, eastern and south-eastern regions covered by Affinity Water, Anglian Water, Essex and Suffolk Water, South East Water, Southern Water, Sutton and East Surrey Water and Thames Water. As a result, it gave water companies in the most water-stressed areas the right (but not compulsory right) to suggest and enforce them. Southern Water already has them.  

The following areas are deemed by the Secretary of State to be classed as water stressed (as of 2021):

• Cambridge Water

• Portsmouth Water

• South Staffordshire Water

• Severn Trent Water – excluding Chester zone

• Veolia Water

• Wessex Water

• South West Water – Bournemouth

• South West Water – Isles of Scilly

The companies determined to be in areas of serious water stress in 2013 remain so:

• Affinity Water

• Anglian Water – East Anglia

• Essex and Suffolk Water 

• SES Water

• South East Water

• Southern Water

• Thames Water

Can You Change Back from a Water Meter to Unmetered?

Yes, you can. The regulators Ofwat and water companies strongly advise customers to get a meter fitted to save money on their water bills, but with many providers, you have two years to assess whether having metered water is worth it and, if you decide it isn't right for you, you can ask your water company to switch you back to an unmetered bill. 

How do Water Companies Read Water Meters?

Water companies themselves may send someone round to check your meters themselves once or twice a year. This isn’t just to check the readings. Water meters can also give indications of any leaks that may need to be addressed. Increasingly, though, smart meters send this information back to them in real-time, negating the need for visits. 

For both residential and business customers, water meters remain a viable way of both saving money and conserving resources. You can be billed for only what you use, while being able to monitor your water usage, giving you greater insight into how you can use less of it. The benefits can be considerable, so if you haven’t already got one, it’s worth looking into getting one installed today!