Dŵr Cymru Welsh Water launches Storm Overflow Map

15 May 2024

As part of its commitment to being open and transparent about the performance of its storm overflows, Dŵr Cymru Welsh Water has developed an interactive map which provides near real-time information about the operation of its storm overflows.

The beta version of the map went live on 1 February 2024, and has undergone a three-month testing period ahead of its public launch this week, to coincide with the start of the UK bathing season.

The storm overflow map is a digital tool which can be accessed on Welsh Water’s website at www.dwrcymru.com/stormoverflowmap. It allows customers and water users in Wales to find out if sensor monitors on Welsh Water’s overflows indicate if they are operating, not operating or if they have operated recently (in the past 24 hours).

The map is accessible on mobile and other devices and provides other useful information about each asset, such as the date and time of the last recorded instance of the overflow operating and any known maintenance issues.

This map launch builds on existing work that Welsh Water is undertaking to ensure that it is being open and transparent about the operation of its storm overflows. It is hoped that the map will help swimmers make an informed decision before entering the water, alongside other planning tools and considerations – such as checking the weather, tides and visiting Natural Resources Wales’ bathing waters webpage.

However, the map does not give information on water quality because there are many things outside of the control of Welsh Water which can impact bathing and river water quality. This can include rural land run, highway run off and private sewerage systems.

Welsh Water’s storm overflow map was developed with the valuable input of potential users. Over a hundred individuals and organisations were consulted during the design phase of the map. Seventy participants representing regulatory bodies, open water swimming groups, campaign groups, local authorities and Welsh Government and UK Government representatives attended demo sessions and their feedback helped shape the design during the development stage.

This group were also notified of the beta version of the map going live in February, giving them an opportunity to use, test and feedback on the map ahead of its public launch.

Representatives of the open water swimmers’ network Bluetits attended one of the early demo sessions and their members have been using the map over the past three months.

Sian Richardson from Bluetits said: “The Bluetits welcome the launch of this easy-to-use interactive map by Welsh Water, which provides swimmers and dippers in Wales with up-to-date information about its storm overflow activity. This kind of information helps open water swimmers like us make a decision before we take a dip.

“As a global organisation we very much hope that this becomes the norm for water companies so that there is greater transparency about storm overflow performance and visibility of their operation for all water users.

Welsh Water’s storm overflow map currently shows storm overflow activity for the assets close to designated bathing waters, non-designated swimming sites which were identified via a Welsh Water swim survey, and shellfish sites. This approach meets Welsh Water’s environmental regulatory commitments.

More inland storm overflows are now being added incrementally to the map in batches over the coming months until all 2,300 of Welsh Water’s assets are showing by March 2025.

Steve Wilson, Managing Director Wastewater Services at Dwr Cymru, said: “We know how important our coastal waters and rivers are to our customers, and we take our role in helping to protect their quality very seriously. Because we’re committed to being open and transparent, we want to ensure our information is easily accessible, so we have developed the storm overflow map which allows customers to see, in near real time, what a storm overflow is doing.

“The launch of this new digital map marks a major step in the sharing of information with our customers and water users in Wales and we hope that this tool will be useful, so that they can see when storm overflows are operating.

“We’re grateful for the support and feedback we’ve had from a range of organisations and individuals during the design, development and testing stages of this project – this has helped us ensure that the map is user friendly and accessible