Location
Sheffield with hybrid working across regional offices including London, Leeds, Newcastle, Sheffield, Derby, and Warrington. Flexible arrangements supported to balance collaboration and focused technical work.

Hours
Full Time - flexible working patterns available

Salary
Negotiable

About the Role
Tetra Tech’s Water Consultancy is seeking a Principal Wastewater Modeller to lead technical delivery and team development across AMP8 and AMP9 wastewater programmes. You will define catchment strategies, lead hydraulic modelling and design inputs from feasibility through to detailed design, and take responsibility for HSE, quality, and governance on multi‑million‑pound projects. Day‑to‑day responsibilities include overseeing modelling standards, managing commercial performance and risk, developing bids and proposals, and representing the business to clients and delivery partners nationwide.

In this role, you will immediately raise modelling assurance and guide complex catchment interventions. Over the medium term, you will build and mentor high‑performing modelling teams, embed improved workflows, and influence investment decisions that reduce pollution and flood risk. Longer term, the role offers strategic influence over national modelling standards, opportunities to innovate with digital tools, and the chance to shape low‑carbon, resilient solutions across major water company frameworks.

Core capabilities include hydraulic modelling leadership with proven expertise in InfoWorks ICM, technical assurance and governance to deliver auditable and compliant outputs, commercial and programme performance management, team leadership and client engagement, and driving digital innovation using GIS, Python, FME, Power BI or similar tools to automate workflows and enhance evidence‑based decision making.

Experience
Proven expertise in hydraulic modelling, particularly with InfoWorks ICM including model development, calibration, and deriving robust catchment strategies. Experience managing commercial risk, resource planning, and contributing to bid and proposal development. Demonstrated ability to lead, mentor, and grow multidisciplinary teams and present complex findings clearly to clients and stakeholders.

About you
Strong leadership skills with a passion for technical excellence and innovation. Ability to work collaboratively across teams and clients, driving continuous improvement and embedding quality and HSE governance. Comfortable working in a hybrid environment with regular client and site visits. Motivated to influence strategic decisions and deliver sustainable, low-carbon water solutions.

Qualifications
Degree in a relevant technical discipline; postgraduate qualification desirable. Chartered status or working towards chartership and professional affiliation (CIWEM, ICE, IWater) preferred.