Location
London

Hours
Full Time

Salary
Negotiable

About the Role
Arcadis is the world's leading company delivering sustainable design, engineering, and consultancy solutions for natural and built assets. With over 36,000 people in more than 70 countries, we are dedicated to improving quality of life. As a Principal Clean Water Modeller, you will provide technical leadership in the development and application of clean water (potable water) distribution network models. You will support planning, resilience, operational strategy, and capital delivery projects, leading the quality assurance of modelling outputs. Working closely with clients and internal teams, you will define robust, fit-for-purpose modelling approaches that support sustainable outcomes and Arcadis’ purpose of improving quality of life.

Role Accountabilities
- Act as technical lead for clean water modelling commissions, defining modelling strategies and ensuring outputs are fit for purpose.
- Provide independent technical assurance, model reviews, and sign-off of deliverables with clear audit trails.
- Develop and promote best practice, guidance, and standard templates across the modelling community.
- Build, update, and maintain clean water network models (steady-state and extended period simulation).
- Undertake demand allocation, asset representation (pumps, PRVs, reservoirs, tanks), and operational control logic.
- Carry out calibration and validation against flow, pressure, and level data.
- Deliver scenario modelling to support growth, resilience, outage planning, pressure management, leakage reduction, and investment planning.
- Ensure compliance with client modelling specifications and water company standards.
- Maintain rigorous documentation, change control, and model development records.
- Lead technical discussions with clients, clearly explaining assumptions, limitations, and results.
- Support scope definition, data strategy, and confidence assessment at project inception.
- Mentor and develop junior and senior modellers, supporting technical excellence and capability growth.
- Contribute to resource planning, task leadership, and a collaborative team culture.
- Support bids and proposals, including defining modelling methodologies, scope, programme, and fee inputs.

Experience
Significant experience in clean water distribution network modelling within consultancy or water company environments. Proven ability to produce high-quality technical documentation and quality assurance records. Strong understanding of water distribution hydraulics and operational behaviour.

About you
Technical leader with excellent communication skills to engage clients and internal teams. Ability to mentor and develop modelling teams. Committed to best practice, quality, and continuous improvement. Collaborative and proactive in supporting business growth and project delivery.

Qualifications
Degree (or equivalent experience) in Civil Engineering, Water Engineering, Environmental Engineering, or a related discipline. Experience with clean water modelling software such as InfoWorks WS Pro, Synergi Water, or EPANET. Proficient with GIS platforms (ArcGIS / QGIS) and data analysis tools (Excel, Python, databases).

Desirable
Chartered status or working towards chartership with a relevant professional institution (e.g. ICE, CIWEM). Experience with water quality modelling concepts (e.g. water age, chlorine decay). Experience developing automation, QA tools, or advanced GIS/data workflows.