Routine maintenance at Hatfield Reservoir

Maintenance works at Hatfield Reservoir

We’ll be carrying out a routine inspection and clean of the facility which extends the lifespan of the Reservoir. This essential work helps us to continue supplying high-quality, reliable drinking water to you and your local community long into the future. These works also help us to proactively maintain water quality, protect the structure of the reservoir and meet our regulatory requirements.

What we are doing

We inspect our reservoirs every few years, to check their structure and carry out any improvements necessary to extend their lifespan. This involves draining the reservoir, cleaning it thoroughly and testing the water quality before returning it to service.

When we’ll be working

Dates: This work will start on Monday 20th October 2025 and will continue for approximately 2–3 months.

We will be updating this page as we progress through the inspection.

How will this affect you?

You may notice slightly lower water pressure while the reservoir works are being carried out. Don’t worry, your water supply will continue as normal, and we'll do everything we can to keep any impact to a minimum.

If you rely on water for medical reasons, please let us know or sign up to our Priority Services Register.

Thanks for your patience while we carry out this important work. If you’d like more information, get in touch with us and quote the project code: P023547.

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About the works

Why is the work at Hatfield Reservoir necessary?

We’re carrying out a routine inspection and clean of Hatfield Reservoir, which supplies your area. We will begin on Monday 20 October 2025 and it is expected to take around 2–3 months to complete, depending on the inspection findings.

Our reservoirs are inspected every few years to check their condition and ensure they continue operating safely and efficiently. This work involves draining the reservoir, inspecting the structure, cleaning it thoroughly, and carrying out any necessary improvements to extend its lifespan and maintain water quality.

Regular cleaning helps us maintain excellent water quality. It also allows our engineers to carry out important structural checks to ensure the reservoir continues to operate safely and efficiently.

The maintenance is being delivered by Affinity Water and our specialist contractors. The Water Quality testing is carried out by Affinity Water’s engineers and laboratories in accordance with Drinking Water Inspectorate regulations.

What happens once the work is complete?

Once cleaning and testing are finished, the reservoir will be refilled and returned to service, helping ensure a reliable and resilient water supply for many years to come.

How big is Hatfield Reservoir and why can’t I see it?

Hatfield reservoir is one of our clean water storage tanks, it is an enclosed structure to safeguard water quality. This design helps protect water quality, reduces evaporation, and ensures the security of the public water supply.

Water supply and billing

Will my water supply be affected?

Your water supply will continue as normal throughout the works. However, you may notice a slight reduction in water pressure while the reservoir is temporarily out of service. We’ve put measures in place to keep any impact to a minimum.

Will my water quality be affected?

No, the work is being carried out to maintain and improve water quality. Once cleaning and inspection are complete, the reservoir will be thoroughly tested before being brought back into service.

Can I still use water as usual?

Yes. You can continue to use your water as usual. There is no need to take any action during this period.

What happens to the water that’s drained from the reservoir?

We carefully manage this process to minimise waste and environmental impact, following strict regulations to protect local watercourses and wildlife.

Will my water bill be affected by this work?

No, this project will not directly affect your water bill. It is part of Affinity Water’s existing investment programme, which is already included within our long-term plans agreed with the industry regulator, Ofwat.

There will be some price rises as part of Ofwat’s approved five-year plan for all water companies over the coming years. These are designed to support essential investment in improving water supplies and protecting the environment.

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