Senior Mechanical Design Engineer - Water Location: Chatham, Kent (flexible hybrid) Job type: Long-term Contract (Outside IR35) A leading water client is seeking an experienced mechanical design engineer to support long-term capital delivery programmes. This client-side position covers the full project lifecycle including feasibility, optioneering, detailed design, construction and commissioning. Responsibilities * Lead mechanical engineering design activities from feasibility through to commissioning on clean water infrastructure projects. * Produce and review detailed mechanical designs, calculations, specifications, reports and drawings for treatment plant assets, pumped systems, pipework and chemical dosing equipment. * Carry out and validate hydraulic calculations, including pump sizing, system curves, head loss assessments and surge considerations. * Ensure design outputs comply with client standards, WIMES, CDM requirements and relevant industry legislation. * Coordinate with multidisciplinary teams including process, civil, electrical and MEICA disciplines. * Undertake site surveys, inspections, testing and commissioning support. * Review contractor design submissions, ensuring technical accuracy, constructability and alignment with client specifications. * Support project managers by contributing technical input to project documentation, programme development and delivery planning. * Maintain strong working relationships with internal teams, stakeholders and framework partners. Requirements * HNC/HND or degree in mechanical engineering or equivalent. * Demonstrated experience delivering mechanical design within water or utilities projects, ideally including treatment and clean water infrastructure. * Strong capability in producing and reviewing mechanical calculations, specifications and technical reports to senior engineer level. * Knowledge of WIMES, water treatment processes, pumping systems, hydraulic analysis and industry standards. * Ability to work autonomously, manage competing priorities and deliver high-quality outputs across multiple live projects. * Effective communication and collaboration skills for multidisciplinary coordination. * Full UK driving licence for travel across client's supply area. This is an excellent opportunity to join a major water client delivering essential infrastructure projects. It offers stability, flexibility and the chance to contribute across the full project lifecycle while working within a supportive, multidisciplinary environment