Principal Mechanical Engineer, Water Sector

Work with Us. Change the World.

At AECOM, we're delivering a better world. Whether improving your commute, keeping the lights on, providing access to clean water, or transforming skylines, our work helps people and communities thrive. We are the world's trusted infrastructure consulting firm, partnering with clients to solve the world’s most complex challenges and build legacies for future generations.

There has never been a better time to be at AECOM. With accelerating infrastructure investment worldwide, our services are in great demand. We invite you to bring your bold ideas and big dreams and become part of a global team of over 50,000 planners, designers, engineers, scientists, digital innovators, program and construction managers and other professionals delivering projects that create a positive and tangible impact around the world.

We're one global team driven by our common purpose to deliver a better world. Join us.

Start here. Grow here.

Are you ready to shape the future of water infrastructure?

We’re looking for a Principal Mechanical Engineer to join our growing Water team, with opportunities to be based across our South East offices - Basingstoke, Croydon, London Aldgate and St Albans.

In this role, you’ll play a key part in delivering major UK water utility investment programmes, supporting the design and delivery of projects that range from small rural sites to multi-million-pound infrastructure and non-infrastructure schemes. These frameworks are long-term and extend through AMP8 and AMP9, giving you the chance to contribute meaningfully to sustainable water solutions across multiple regions.

You will support the delivery of several high-value capital programmes, including:

• South West Water - Framework for Engineering Consultancy Services:

  Lot 3 - Multi-Discipline Engineering Design

• Wessex Water - Capital Delivery Partner Framework Agreement:

  Lot 2 - Design Consultant

• Severn Trent Water - Lot 1 Major Projects Framework:

  Supporting AMP8 delivery plan valued at a TotEx of £14.9 billion

• Severn Trent D&B Projects - Supporting Tier 1 contractors on major non-infrastructure wastewater schemes
• Southern Water Strategic Delivery Partner (SDP) Frameworks:
  • Lot 1: Non-infrastructure water projects
  • Lot 2: Non-infrastructure wastewater projects
• Southern Water Low Complexity and Infrastructure Frameworks:
  • Lot 2: Wastewater Infrastructure
  • Lot 3: Infrastructure Framework - Partnering exclusively with Tier 1 contractors to deliver efficient and sustainable water and wastewater solutions

Working flexibly, you’ll visit client sites and collaborate with teams across multi-year frameworks. As part of our thriving business, you’ll take on rewarding multi-disciplinary projects from inception to delivery, creating innovative solutions that enhance the environment and improve communities.

Here's what you'll do:

• Develop feasibility studies, outline and detailed designs, and provide construction support.
• Create design drawings, select mechanical plant, and prepare technical specifications.
• Collaborate with multidisciplinary teams, including civil, electrical, process, and mechanical engineers.
• Ensure high technical quality, contribute to bids, and maintain client relationships.
• Manage project budgets, schedules, and deliverables to meet agreed targets.
• Design mechanical installations for water and wastewater systems, including pumps, screens, valves, and odour control.
• Conduct site surveys and liaise with clients, contractors, and suppliers.
• Produce layouts, technical specifications, datasheets, and P&IDs for system designs.

As well as providing innovative and industry leading MEICA solutions to Clients, the team also collaborates with a wide variety of disciplines from other offices in delivering projects, including a close working relationship with our Enterprise Capabilities centres in India, South Africa and Romania.

Come & Grow With Us.

Become part of our dynamic Water business, which boasts over 600 experts across the UK & Ireland, including 170 specialists across our England & Wales Water Solutions team. Collaborate with top-tier civil, mechanical, electrical, and process engineers to deliver a variety of captivating projects, from small initiatives to large-scale ventures, all the way from concept to completion. Here, you’ll thrive in an inclusive and forward-thinking environment where your contributions are valued.

Enjoy the Perks.

At AECOM you'll enjoy a range of core and personalised benefits designed to support your future and well-being, customised to fit your lifestyle. Take advantage of career development opportunities, our flexible hybrid working model to ensure a work-life balance that suits your lifestyle, technical practice networks, AECOM University, and volunteering days.

Ready to push the limits of what’s possible?

Here’s what we’re looking for:

• A degree in Mechanical Engineering with Chartered Engineer status (or working towards it) through a recognised institution like IMechE.
• Proven expertise in producing, reviewing, and approving engineering reports, designs, drawings, and specifications.
• A problem-solver at heart, confident in taking ownership of challenging technical issues and seeing them through to resolution.
• Leadership potential, able to manage direct reports, inspire technical excellence, and support the growth of fellow engineers.
• Exceptional client and stakeholder engagement skills, with experience in team leadership, mentoring, and line management.
• Experience in the water and/or wastewater industry.

We celebrate diversity, including neurodiversity, and believe it enriches our team. We welcome applications from all backgrounds and abilities. If you are an applicant with a disability that requires reasonable accommodation to complete the application process, please contact us at [email protected]. At AECOM, we value everyone's unique contributions and perspectives.

If you meet some of the requirements above or have transferable skills you believe would benefit us, we would be delighted to hear from you!

Interested in the role or curious about life at AECOM? Follow us on LinkedIn, Facebook, Instagram, and YouTube to explore our AECOM voices, employee stories, latest projects, and much more!

For further information about the role, reach out to the recruiter on LinkedIn (3) Anne Marie Flynn | LinkedIn

About AECOM

AECOM is the world’s trusted infrastructure consulting firm, delivering professional services throughout the project lifecycle - from advisory, planning, design and engineering to program and construction management. On projects spanning transportation, buildings, water, new energy and the environment, our public- and private-sector clients trust us to solve their most complex challenges. Our teams are driven by a common purpose to deliver a better world through our unrivaled technical and digital expertise, a culture of equity, diversity and inclusion, and a commitment to environmental, social and governance priorities. AECOM is a Fortune 500 firm and its Professional Services business had revenue of $16.1 billion in fiscal year 2025. See how we are delivering sustainable legacies for generations to come at aecom.com and @AECOM.

Freedom to Grow in a World of Opportunity

You will have the flexibility you need to do your best work with hybrid work options. Whether you’re working from an AECOM office, remote location or at a client site, you will be working in a dynamic environment where your integrity, entrepreneurial spirit and pioneering mindset are championed.

You will help us foster a safe and respectful workplace, where we invite everyone to bring their whole selves to work using their unique talents, backgrounds and expertise to create transformational outcomes for our clients.

AECOM provides a wide array of compensation, benefits and well-being programs to meet the diverse needs of our employees and their families. We’re the world’s trusted global infrastructure firm, and we’re in this together - your growth and success are ours too.

Join us, and you’ll get all the benefits of being a part of a global, publicly traded firm - access to industry-leading technology and thinking and transformational work with big impact and work flexibility. As an Equal Opportunity Employer, we believe in each person’s potential, and we’ll help you reach yours.

We are a Disability Confident Employer and will offer an interview to applicants who have a disability or long-term condition, who meet the minimum/essential criteria for the role. Please let us know using this email address [email protected] if you would like to apply through the Disability Confident Interview Scheme.

All your information will be kept confidential according to EEO guidelines.