Job Description

Principal Mechanical Engineer - Water Sector (Hybrid - Thames Water Region)
Location: Maple Lodge Office | Hybrid Working Available
Salary: Competitive | Excellent Benefits Package
We are currently seeking a highly experienced Principal Mechanical Engineer to join a thriving engineering team delivering a major programme of work across the Thames Water region.
This is a long-term, high-value water and wastewater infrastructure project, and an excellent opportunity to contribute to a dynamic and growing framework partnership as we move into AMP8.
As a recruitment partner to the employer, we are proud to present this opportunity for a skilled mechanical engineering professional to take the lead on complex design and delivery across a portfolio valued at 400M+.
The role offers a mix of office-based and hybrid working, and the opportunity to shape critical design outcomes while mentoring developing engineers within a collaborative, multidisciplinary environment.
Key Responsibilities:
Lead and deliver mechanical design solutions from concept through to detailed design and delivery.
Produce and check technical documents including specifications, schedules, drawings, and calculations.
Coordinate multi-disciplinary design teams, ensuring outputs are aligned and on programme.
Oversee development of 3D plant models and promote design standardisation where possible.
Drive buildability, efficiency, and sustainability in all design outputs.
Liaise with construction and supply chain partners to ensure seamless project delivery.
Champion health & safety and regulatory compliance including CDM 2015.
Support design and operability workshops, contributing to robust, maintainable solutions.
Mentor junior staff and assist in their technical and professional development.
About You:
To be successful in this role, you will bring:
A degree in Mechanical Engineering (or relevant discipline) and Chartered status.
Strong technical knowledge of mechanical design in water and wastewater treatment.
Proven experience leading design teams on complex infrastructure projects.
Good understanding of associated disciplines (process, electrical, civil) and their integration.
Knowledge of industry standards (WIMES, BS, BSRIA), HSE legislation and Water Quality Regulations.
Excellent communication skills and ability to present technical proposals clearly.
A proactive, adaptable approach to problem-solving and teamwork.
A valid UK driving licence.
Benefits:
In return, you will receive:
Competitive salary
25 days annual leave (plus bank holidays, with the option to buy additional days)
Generous pension contribution
Electric car scheme
Loyalty award scheme
Hybrid working options (role-dependent)
Life assurance and private medical insurance
Health insurance and well-being support
Cycle to work scheme, retail discounts, and more
This is an exciting opportunity to join a highly respected engineering organisation that truly values its people and supports long-term professional development. The position offers both technical challenge and career progression within a business committed to excellence, diversity, and environmental stewardship.
Interested?
Apply now to take the next step in your engineering career and help deliver innovative, sustainable water infrastructure that will serve communities for years to come.
Company information
At First Recruitment Group we understand just how important it is to secure the right people. That is why our Recruitment Consultants always take the time to understand requirements in detail and offer sound advice to both clients and candidates. We actively recruit at all levels and this is a superb opportunity for Mechanical Engineers looking for new employment.
As part of putting people first, we strive to be an equal opportunities employer and we are always looking to increase the diversity of our workforce, working closely with our clients to ensure everyone is included.