Senior hydraulic modeller

Senior hydraulic modeller Overview

Arup is seeking a senior or principal wastewater hydraulic modeller to join its Cardiff-based water engineering team. The role sits within a multidisciplinary technical delivery group that works on a broad range of projects for clients across Wales and southwest England, with a strong focus on catchment-scale wastewater modelling, design, and investment programmes that improve river and coastal water quality. The position also connects into Arup’s wider global modelling centre of excellence, giving the successful candidate the chance to influence technical delivery locally while contributing to international work and wider capability building.

This opportunity is aimed at someone who can take a leading role in wastewater network modelling across the full project lifecycle. The work spans strategic planning, feasibility, detailed design, and design-and-build support, so the role offers the chance to see solutions progress from early concept through to delivery. The team places strong emphasis on sustainability and nature-based solutions, and the successful applicant will be encouraged to help shape innovative approaches that support long-term environmental, social, and economic outcomes.

What you will do

• Lead wastewater network modelling assignments from early planning through to detailed design and implementation support.
• Work on catchment-scale wastewater modelling and design projects for local clients in Wales and southwest England.
• Contribute to programmes linked to WINEP/NEP and storm overflow investment, helping improve rivers and coastal waters across the region.
• Use 1D hydraulic models to carry out detailed risk analysis and develop solutions that reduce flood risk and improve water quality.
• Focus particularly on storm overflows and wastewater treatment works when developing modelling and design responses.
• Take a leadership role within the Cardiff/Bristol/Birmingham modelling centre of excellence.
• Manage and mentor junior modellers, helping to build technical capability within the team.
• Support the development of overseas teams across Arup’s global business.
• Contribute to Arup’s global training programme for modelling.
• Prepare technical reports, model builds, analytical outputs, business cases, multi-capitals economics inputs, supporting calculations, and other key deliverables.
• Work alongside civil engineers, digital specialists, and expert modellers in a blended multidisciplinary environment.
• Help develop and apply digital tools that improve, optimise, and automate the team’s services.
• Participate in Arup’s internal research and innovation activity, including work that informs industry guidance and digital products.
• Build and maintain strong relationships with client teams, including operations, asset management, environmental, and modelling stakeholders.
• Contribute to holistic catchment solutions with a strong focus on nature-based approaches.
• Support international water projects for Arup’s global business in locations such as Manila, India, Australia, and across North and South America.

What the team and role offer

The successful candidate will join a passionate and collaborative water team that works across the full water cycle, from infrastructure design and maintenance to catchment and flood defence advice. The role is part of a wider culture that values mentoring, professional growth, and investment in new ideas. Arup also invests in bespoke research and development each year, often in partnership with others, to expand knowledge, create guidance, and build digital tools and products. This means the role is well suited to someone who wants to combine technical delivery with innovation, leadership, and knowledge sharing.

What you need

• Strong experience in hydraulic modelling within the UK water industry.
• Hands-on expertise with InfoWorks ICM, with Level 1 UPM water quality modelling experience preferred.
• A degree, or equivalent qualification, in engineering, geography, environmental science, or a similar subject.
• Professional chartership with a relevant organisation.
• A strong history of successfully delivering water projects in the UK.
• Experience working with both private and public sector clients, as well as regulators.
• Excellent skills in managing client relationships.
• Confidence when presenting results, issues, and proposals in a collaborative setting.
• Ability to contribute to the development of digital tools that streamline and enhance service delivery.
• Capability to lead, mentor, and support junior team members.
• Interest in sustainability-led and nature-based solutions.
• Comfort working across multidisciplinary teams and contributing to research and innovation.

Reward, wellbeing, and inclusion

Arup offers a total reward package designed to support members’ success and long-term growth. In addition to competitive, fair, and equitable pay, the package includes profit share, private medical insurance, life assurance, accident insurance, and income protection cover. Flexible benefits are also available so employees can tailor support to their own wellbeing and family needs.

The organisation describes itself as owned in trust for its members, which gives it the freedom to choose work aligned with its purpose and values. Employees are encouraged to collaborate on ambitious projects that deliver meaningful outcomes for clients and communities, while also benefiting from learning opportunities and career development support.

Arup is committed to being an equal opportunity employer and actively seeks a diverse and inclusive workforce. Applications are welcomed from people of all backgrounds, and the company highlights its support for inclusion across race and cross-cultural working, gender equity, LGBTQ+ inclusion, and disability inclusion. The workplace is intended to be open, respectful, and welcoming of different experiences and perspectives.

The company also says it is committed to accessibility in recruitment and the workplace. Candidates who need assistance or reasonable adjustments during the application or interview process, or to carry out the essential duties of the role, are encouraged to get in touch so support can be arranged.

How to apply

Applications should be submitted through Arup’s careers process for this vacancy. If you have questions before applying, you can contact [email protected], but you should not send your CV directly to that email address because the company asks applicants to avoid doing so for GDPR reasons. Arup states that all applications will be reviewed and that it aims to respond within 72 hours of receiving them, although replies may take longer during the festive period. The closing date shown on the page is 23 July 2026, and the company notes that it may close the role earlier if it receives a high volume of applications, so early submission is encouraged.

Degree Requirement: Not Specified

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