British Water, the leading supply chain membership organisation for the UK water sector, has announced the appointment of Stephen Slessor, Chief Executive of RSE, as its new chair. He takes over from Dr Mark Fletcher, Director and Global Water Business Lead at Arup, who steps down after three years.

Stephen Slessor brings a quarter-century of extensive sector experience, encompassing engineering, digital construction approaches, and strategic leadership. He has led RSE, a water technology company specialising in modular solutions for water and wastewater treatment, since January 2024, overseeing a period of significant growth and expansion.

Commenting on his appointment, Mr Slessor said: “I’m humbled to step into the role as chair of British Water as the water sector steps up to meet the most pressing challenges in the coming decades, whether that be related to climate, regulatory changes or skills development. The input and innovation of our growing membership is more critical than ever in delivering a more sustainable and resilient UK water ecosystem, and I will endeavour to champion the vital work of British Water at every turn.”


Lila Thompson, Chief Executive of British Water, expressed her delight: "We are delighted to welcome Stephen Slessor as chair of British Water. He brings deep industry expertise and a forward-thinking approach at a time when the water sector is undergoing significant transformation. Stephen’s passion for innovation and commitment to collaboration align strongly with the British Water mission of supporting a sustainable and high-performing water sector. I look forward to working with him as we continue to champion the voice of the supply chain and drive meaningful change across the industry.”

Slessor’s appointment is particularly timely for the UK water sector, aligning with British Water’s vision for a world-leading, outcome-focused industry. The trade body supports its members through a diverse portfolio of events, forums, and focus groups. As chair, Mr Slessor will work closely with the British Water board to expand membership, enhance organisational resilience, and hold the Government accountable for its pledges on skills and opportunities for the water sector supply chain.

His appointment follows the recent final report of the Independent Water Commission, which presented 88 recommendations for water sector reform. This report notably supported British Water’s calls for longer-term planning, improved coordination, and a more stable, visible, and integrated infrastructure pipeline. The report also cited findings from British Water’s annual Water & Wastewater Company Performance survey, its supply chain taskforce, and cross-sector procurement working group.

Prior to his role at RSE, Mr Slessor had a distinguished 17-year career at construction company Galliford Try, rising to managing director. He notably led the merger of Galliford Try with NMCN in 2021, a move that created the largest contractor to the UK water sector. He has also previously served as a non-executive director for British Water, held a position on the advisory board of the Scottish Futures Trust, and was president of the Chartered Institute of Civil Engineering Surveyors.

British Water extended its sincere thanks to outgoing chair Dr Mark Fletcher for his invaluable insight and vision during his tenure, confirming that he will continue to work within the wider water community.