Thames Water

Background

As the UK’s largest water and wastewater services provider, Thames Water serves more than 16 million people across London and the South East of England. Its website is the organisation’s primary customer service channel — a platform that must remain secure, performant, and available 24/7.

Traffic can increase dramatically during service incidents, with hundreds of thousands of customers visiting the site to find timely updates. In this highly regulated environment, Thames Water needed a digital platform that could scale reliably while supporting fast, accurate publishing.

However, the organisation’s existing Sitecore platform was no longer meeting these demands. The system suffered from performance and stability challenges, offered a poor experience for content editors, and carried a high commercial cost relative to the value delivered. Thames Water recognised the opportunity to move away from Sitecore and build a stronger business case by improving reliability and changing the cost model.

Solution

Thames Water migrated from Sitecore to Umbraco, selecting a cloud-hosted, headless architecture built on .NET Core, React, and Next.js. The new platform was designed to be secure, scalable, and always available — even during extreme traffic spikes.

Beyond the technical fit, the decision was strongly influenced by the people behind Umbraco. Thames Water valued working with a team that was patient, supportive, and genuinely invested in their success throughout the multi-year journey.

To reduce risk, the team avoided a “big bang” migration. Instead, they launched a single page on Umbraco, routed customers to it, and learned from real usage. Over time, more pages and journeys were added, gradually shifting traffic away from Sitecore while continuously improving the experience.

Nearly 700 pages were migrated, with content teams closely involved to ensure quality and control. The result was a modern, extensible platform that integrates easily with existing systems and supports future growth.

Impact

The move away from Sitecore significantly reduced technical complexity and infrastructure overhead. By eliminating legacy infrastructure and adopting Umbraco Cloud, Thames Water lowered maintenance effort and achieved meaningful cost savings — with infrastructure reductions effectively covering the cost of licensing.

Content teams now work in a clean, intuitive interface that requires little to no training. Publishing is fast and reliable, allowing Thames Water to respond quickly during incidents and ensure customers receive accurate information when it matters most.

Most importantly, Umbraco provides a secure, scalable foundation that Thames Water can continue to extend safely, adding new capabilities without risking platform stability.