Thames Water is looking for a proactive, quality‑driven CSL Assurance Supervisor to play a key role in delivering an exceptional Customer Side Leakage (CSL) service. If you’re motivated by problem‑solving, field supervision, and making a real difference to customer experience, this is an opportunity to shape how we protect our network and support our communities.

What you’ll be doing as the CSL Assurance Supervisor

You’ll be the vital link between our service delivery teams across London and the Thames Valley, field repair partners, and our customers, ensuring all planned and reactive work is completed safely, efficiently, and to the highest standards. Every day will bring variety as you support field teams on the ground, drive quality, and keep customers informed and reassured.

Key Responsibilities

Large Leaks / High‑Profile Jobs

  • Attend sites to support repair gangs and ensure effective delivery.
  • Provide hands‑on supervision and technical guidance for complex or high‑visibility leaks.
  • Maintain live contact with repair partners to monitor progress in real time.
  • Attend customer site visits, helping to build trust and keep communication clear.
  • Proactively remove blockers to keep repairs moving smoothly.

Planned Work Management

  • Review upcoming planned works and guide decisions on scheduling and prioritisation.
  • Help clear blockers such as permits, access challenges, customer availability, or materials.
  • Carry out site visits for complex repairs to assess methods and agree best‑fit solutions.
  • Work closely with the Service Delivery Team to track performance and ensure timely delivery.

Audits & Compliance

  • Complete a minimum of four high‑quality site audits each month.
  • Ensure every audit covers essential H&S, water quality, and workmanship standards.
  • Identify and resolve non‑compliance issues quickly, escalating where needed.
  • Support ongoing reporting to highlight trends and drive continuous improvement.

Abort & Attrition Performance

  • Help monitor abort and attrition levels across repair partners.
  • Assist in live situations where abort risks appear, escalating as appropriate.
  • Share insights and data with partners to reduce avoidable aborts.
  • Improve outcomes through proactive planning and consistent on‑site presence.

Key Deliverables

  • Minimum of four compliant site audits per month, with full evidence.
  • Active, consistent engagement with repair teams and customers.
  • Ongoing compliance with H&S, water quality, and workmanship expectations.
  • Reduction in abort and attrition rates through effective supervision and planning.

What you should bring to the role

  • Demonstrable experience working within a CSL operation is essential, including hands‑on operational understanding of how CSL repairs are delivered in the field, and the practical problem‑solving required to complete jobs where access, customer or technical challenges arise.
  • Experience in a supervisory or field‑based role within the water industry.
  • Strong understanding of leakage repair, reinstatement, and network operations.
  • Excellent working knowledge of H&S, NRSWA, and water hygiene standards.
  • Confident communicator able to liaise with customers, repair partners, and internal teams, with the
  • Ability to assess issues on site and make sound, quick decisions.
  • Competent IT skills for reporting and updating systems accurately.

Location: Hybrid - Field Based - Base Location Maple Lodge - Rickmansworth - WD3 9SQ

Hours: 36 hours per week

What's in it for you?

  • A competitive salary starting of £46,000 per annum
  • 26 days holiday per year, increasing to 30 days with the length of service. (plus bank holidays)
  • Performance-related pay plan directly linked to company performance measures and targets.
  • Generous Pension Scheme through AON.
  • Access to lots of benefits to help you take care of you and your family’s health and wellbeing, and your finances – from annual health MOTs and access to physiotherapy and counselling, to Cycle to Work schemes, shopping vouchers and life assurance.

Find out more about our benefits and perks

Who are we?

We’re the UK’s largest water and wastewater company, with more than 16 million customers relying on us every day to supply water for their taps and toilets. We want to build a better future for all, helping our customers, communities, people, and the planet to thrive. It’s a big job and we’ve got a long way to go, so we need help from passionate and skilled people, committed to making a difference and getting us to where we want to be in the years and decades to come.

Learn more about our purpose and values

Working at Thames Water

Thames Water is a unique, rewarding, and diverse place to work, where every day you can make a difference, yet no day is the same. As part of our family, you’ll enjoy meaningful career opportunities, flexible working arrangements and excellent benefits.

If you’re looking for a sustainable and successful career where you can make a daily difference to millions of people’s lives while helping to protect the world of water for future generations, we’ll be here to support you every step of the way. Together, we can build a better future for our customers, our region, and our planet.

Real purpose, real support, real opportunities. Come and join the Thames Water family. Why choose us? Learn more.

We’re committed to being a great, diverse, and inclusive place to work. We welcome applications from everyone and want to ensure you feel supported throughout the recruitment process. If you need any adjustments, whether that’s extra time, accessible formats, or anything else just let us know, we’re here to help and support.

When a crisis happens, we all rally around to support our customers. As part of Team Thames, you’ll have the opportunity to sign up to support our customers on the frontline as an ambassador. Full training will be given for what is undoubtedly an incredibly rewarding experience. It’s also a great opportunity to learn more about our business and meet colleagues.

Disclaimer: due to the high volume of applications we receive, we may close the advert earlier than the advertised date, so we encourage you to apply as soon as possible to avoid disappointment.