How water works

Due to the nature of aquifers and how they function, the most important factor is how much rainfall we get during autumn and winter. This is because groundwater levels are effectively ‘topped up’ during this time, by the amount of rainfall that filters down through the soil. This process is known as “recharge".

The ground needs to be wet (have a certain level of moisture) for water to seep through and for recharge to happen. We measure this through a metric called ‘soil moisture deficit’ or ‘SMD’. The higher SMD is, the drier the soil is. This means it is less likely that rainfall will filter down to contribute to recharge our aquifers. On the other hand, the lower SMD is, the more likely it is that a higher proportion of rainfall will contribute to recharge.

During the summer, the ground tends to be hard and dry. This means that if it rains during the summer, this has little to no effect on the Chalk groundwater levels as it’s harder for the water to seep through the soil. Instead of seeping through to groundwater, the rain runs off into rivers or the drainage network. Water falling during warmer months is also more likely to be used by plants/vegetation or evaporate. Therefore, we’re more reliant on receiving rainfall during the autumn/winter months, as the rain is more likely to seep through the soil.

Droughts can affect water companies in different ways, as all water companies have different sources of supply (i.e. how much comes from groundwater and how much comes from surface water). Each water company produces a Drought Management Plan, which sets out the actions they take during a drought to ensure that they can continue to supply water to their customers.

Some of the reasons why drought impacts can vary geographically and between water companies are explained below:

Rainfall isn’t the same everywhere, so some areas can receive less rainfall than other areas. Generally, the Southeast of England receives less rainfall than the rest of the country. Dry winters generally impact groundwater sources as they need to be topped up by winter rainfall.

Dry summers and high temperatures tend to cause high demand for water that generally impact on surface water sources (such as rivers and reservoirs). For example, levels in reservoirs may be drawn down to meet the elevated demand. Water is also lost through evaporation, that doesn’t impact groundwater sources.

Different parts of the areas we serve, use different amounts of groundwater and surface water. This means that some parts of our area can be impacted differently by drought at a given point in time. This may mean that we need to restrict water use (Temporary Use Ban (formerly a hosepipe ban)) in some areas but not others.

For more information about how droughts can affect us as a predominantly groundwater-dominated company, please see our Drought Plan.

For more information about our current water resource situation, please visit our water resources page.

We only take what we need from the environment, based on demand. There are licences in place for how much water we can take. We monitor each of our licences, daily and we only take what we need. We never take more than we’re allowed and this is managed/regulated by the Environment Agency.

We’re investing in capital delivery projects, replacing and installing new mains pipes to reduce future leaks and bursts which helps reduce water wastage and leaves more water in our environment.

Innovative plans are underway to reduce abstraction in the River Ver, River Mimram, Upper River Lea and River Misbourne by summer 2024.

By reducing the amount we take, more water is left in the environment. We face many challenges including population growth and climate change and are actively planning to create a secure and environmentally sustainable water supply in the future. For more information about the plans we are putting in place to meet these challenges, please see our Water Resources Management Plan.

We work closely with the Environment Agency to review the sustainability of our abstraction licences and make changes to how we operate when needed. We’ll be monitoring how the environment is responding to keep track of positive changes. We’re committed to helping our environment, now and in the future.

We conduct 185,000 individual lab tests from compliance samples. We also take hundreds of samples each day from our treatment works to make sure the water we’re treating is always of the highest standard, and we make sure our processes are always efficient and effective.

We’ve achieved a high score on a measure of water quality in what we call the Compliance Risk Index (CRI). The Drinking Water Inspectorate (DWI) does technical audits on water companies to make sure our operating practices are always effective, and they assess our sampling programme, and our sampling results every year. They can also assess specific incidents, to make sure we have the right recommendations and improvement plans in place, and that we investigate any complaints from consumers, and they can enforce any activities. They play a big part in ensuring all the water companies comply with all the regulations and standards. From source to tap we make sure the water is of the right quality.

Find out more about water quality

Extreme weather conditions, such as a freeze-thaw or a heatwave cause pressure on our network, where both the ground and pipes expand and contract. This is one of the main factors that leads to leaky pipes, along with general wear and tear, and this may temporarily interrupt the flow of water to your home.

We have lots of tips online, if you visit the Save Our Streams page you can also take the My Water Footprint quiz to see how much your house could save! We also offer FREE Home Visits, where a qualified technician will come to your home to identify and repair any small leaks (where possible). They’ll also offer to fit free water saving devices, and give you some advice about easy changes you could make to reduce your water and energy bills.

You can check out our wastewater page, where you can see what providers cover our supply area. You can also search for your postcode to see which company operates in your area.