Associate Technical Director - Surge / CFD Modelling

Arcadis is the world's leading company delivering sustainable design, engineering, and consultancy solutions for natural and built assets.

We are more than 34,000 people, in over 30 countries, dedicated to improving quality of life. Everyone has an important role to play. With the power of many curious minds, together we can solve the world’s most complex challenges and deliver more impact together.

Role description:

This is a career-defining opportunity for a recognised technical expert in hydraulic engineering to lead Arcadis's specialist capability in pressure surge (transient hydraulics), Computational Fluid Dynamics (CFD), and advanced hydraulic modelling across water and wastewater infrastructure in the UK and internationally.

As Associate Technical Director, you will be the technical conscience of the Water business for this discipline, setting standards, leading complex studies, building and mentoring a team of specialist engineers, and positioning Arcadis as the go-to firm for clients who need rigorous, innovative hydraulic engineering on their most critical assets.

Working within a major AMP8 framework delivery environment, and operating within a three-tier delivery structure alongside major contractors and direct clients, you will translate advanced hydraulic modelling into practical, defensible engineering solutions that reduce infrastructure risk, improve asset reliability, and inform investment decisions at programme scale.

Role accountabilities:

Technical Leadership & Delivery

• Technical Authority. Act as Arcadis's named technical authority and final reviewer for pressure surge, transient hydraulics, and CFD studies across capital schemes, framework programmes, and operational risk work.
• Complex Modelling. Direct and technically oversee advanced transient and CFD studies, including undulating rising mains, pump-station protection, air entrainment, multiphase flow, priming/draining systems, and treatment plant internal hydraulics, ensuring outputs are defensible and client-ready.
• Standards & Governance. Develop, maintain, and embed Arcadis's technical standards, model assurance frameworks, design guidance, and QA protocols for surge and CFD, ensuring consistency across projects and programmes.
• Tool Expertise. Apply and champion industry-leading modelling platforms including HAMMER, Wanda, VariSim, ANSYS Fluent, OpenFOAM, and related hydraulic analysis tools such as HADES; evaluate and introduce new tools where these advance our capability.
• Innovation & Digital. Drive the integration of data-driven methods, AI/ML applications, digital twin approaches, and automated workflows into hydraulic modelling practice, positioning Arcadis ahead of sector development in this discipline.
• Multidisciplinary Integration. Provide cross-functional technical leadership to water quality, process, civil, and design teams to improve whole-system outcomes and reduce risk across complex, multi-disciplinary programmes.

Commercial Development & Client Ownership

• Client Relationships. Build and maintain trusted technical relationships with major UK water utilities (e.g. Thames Water, Anglian Water, Severn Trent, Southern Water, United Utilities) and contractors, acting as a recognised technical partner rather than a transactional supplier.
• Business Development. Identify, pursue, and win new work, support bid preparation, write technical sections of proposals, attend client presentations, and develop the pipeline for surge, CFD, and hydraulics services within Arcadis's Water Management business.
• Framework Delivery. Lead technical delivery within AMP8 framework programmes, managing Arcadis's obligations and quality standards within complex multi-party delivery structures.
• Commercial Accountability. Manage project finances, including fee negotiation, earned value tracking, cost control, and variation management, to deliver studies profitably and to schedule.
• Thought Leadership. Represent Arcadis at industry conferences (ICE, CIWEM, IMechE, Pipeline Industries Guild), contribute to publications, and build external profile for the firm's hydraulic engineering brand.

People Leadership & Capability Building

• Team Building. Recruit, develop, and lead a high-performing team of hydraulic modelling specialists, from graduate to principal level, growing Arcadis's in-house surge, CFD, and hydraulics capability in a sustainable and structured way.
• Mentoring. Provide hands-on technical mentoring, structured development support, and professional review guidance to engineers working towards chartered status (CEng/CIWEM/IMechE).
• Knowledge Sharing. Lead recurring technical forums, deliver internal training sessions, and support cross-business knowledge exchange to embed hydraulic expertise across Arcadis Water Management.
• Academic & Industry Engagement. Maintain and develop academic links and industry body relationships to attract talent and keep Arcadis connected to the frontier of hydraulic engineering practice.

Qualifications & Experience:

Essential Requirements

• Minimum 12 years of progressive hydraulic engineering experience, with substantive specialisation in pressure surge/transient analysis and/or Computational Fluid Dynamics (CFD) applied to water and wastewater infrastructure.
• Chartered Engineer (CEng) status, with full membership or fellowship of a relevant professional body, CIWEM (FCIWEM/MCIWEM), IMechE, ICE, or equivalent.
• Demonstrated technical authority in transient hydraulic modelling, including surge assessment, pump-station protection design (surge vessels, air valves, variable speed drives), and rising main risk analysis, using tools such as HAMMER, Wanda, VariSim, or equivalent.
• Proven CFD modelling capability using ANSYS Fluent, OpenFOAM, or comparable platforms, applied to water and wastewater treatment plant hydraulics, reservoir mixing, disinfection contact time, or related applications.
• Track record of providing technical governance, authoring assurance frameworks, model QA standards, and design guidance, that improve consistency and quality across programmes.
• Demonstrable experience leading, mentoring, and developing specialist engineering teams, with evidence of growing individual and organisational hydraulic capability.
• Experience working with major UK water utilities and a solid understanding of the AMP regulatory framework, capital delivery structures, and client procurement environments.
• Strong commercial acumen, experience managing project fees, supporting bids and framework submissions, and sustaining profitable client relationships.

Desirable Requirements

• Experience applying AI, Machine Learning, or data-driven analytical techniques to hydraulic engineering problems (e.g. hybrid CFD-ML modelling, anomaly detection in pressure monitoring data, automated calibration).
• Published author of technical journal articles, design guides, or industry reports in pressure surge, CFD, or advanced hydraulic modelling.
• Conference presenter or guest lecturer at university level, demonstrating recognised authority in the field.
• Experience with digital twin development for water infrastructure, integrating live telemetry, SCADA data, and hydraulic models into operational decision-support systems.
• Familiarity with high-frequency pressure monitoring methodology and its integration into transient model calibration and asset management planning.
• Experience working in a sub-consultant or framework delivery environment, navigating three-tier contractual structures.
• IAM Certificate in Asset Management or equivalent qualification in infrastructure asset management.

Why Arcadis?

We can only achieve our goals when everyone is empowered to be their best. We believe everyone's contribution matters. It’s why we are pioneering a skills-based approach, where you can harness your unique experience and expertise to carve your career path and maximize the impact we can make together.

You’ll do meaningful work, and no matter what role, you’ll be helping to deliver sustainable solutions for a more prosperous planet. Make your mark, on your career, your colleagues, your clients, your life and the world around you.

Together, we can create a lasting legacy.

Join Arcadis. Create a Legacy.

Our Commitment to Equality, Diversity, Inclusion & Belonging

We want you to be able to bring your best self to work every day which is why we take equality and inclusion seriously and hold ourselves to account for our actions. Our ambition is to be an employer of choice and provide a great place to work for all our people. We believe that by working together diverse people with different experiences develop the most innovative ideas. Equality, diversity and inclusion is at the heart of how we improve quality of life and we work closely with our people across six ED&I Workstreams: Age, Disability, Faith, Gender, LGBT+ and Race. A diverse and skilled workforce is essential to our success.