Principal Mechanical Engineer – Water

Company: Arup
Apply for the Principal Mechanical Engineer – Water
Location: Cardiff
Job Description:

Overview

As Principal Mechanical Engineer in Arup’s Water team, you lead the mechanical design of water and wastewater projects from feasibility to construction. You’ll own solutions for treatment, pumping, and pipework within major UK utilities frameworks, guiding multidisciplinary teams and engaging clients to meet time, budget, and technical targets. You’ll advance digital design using BIM and Plant 3D while contributing to bids and driving a culture of rigour and innovation. This is a chance to shape essential water infrastructure with a respected, values-driven firm.

Pay / Benefits

  • profit share
  • private medical insurance
  • life assurance
  • income protection
  • flexible benefits
  • learning opportunities

Responsibilities

  • Lead mechanical design and delivery of water sector projects from feasibility through construction
  • Provide technical direction to multidisciplinary teams focusing on treatment, pumping, and pipework design
  • Oversee and mentor junior engineers and technicians to ensure high standards
  • Engage directly with clients to define technical requirements, timelines and budgets
  • Contribute to work-winning activities including bids, proposals, and client meetings
  • Utilise BIM and Plant 3D to enhance project outcomes and digital delivery
  • Promote technical rigour, operational efficiency, and innovative solutions within the team

Key requirements

  • Proven experience delivering mechanical designs in the water utilities sector (treatment facilities, pumping systems)
  • Chartered Engineer (CEng) status with IMechE or progressing toward chartership
  • Strong knowledge of UK mechanical design standards and practices in water
  • Proficiency with digital design software (BIM, Plant 3D)
  • Clear communication and ability to work in multidisciplinary teams
  • Results-oriented with ability to manage priorities and deliver quality on time
  • clear communication
  • leadership
  • problem solving
  • BIM
  • Plant 3D
  • water treatment facilities design

…

Posted: October 11th, 2026