Design Manager – Water & Wastewater Location: Southern Water Region Contract Type: Permanent Sector: Water Infrastructure / AMP8 CMDP has secured a new AMP8 Capital Programme Strategic Delivery Partner Framework Agreement with Southern Water for Water and Wastewater delivery. This award continues the successful joint venture partnership between Costain and MWH Treatment. The framework has been awarded for an initial seven-year term, with the option to extend for up to a further five years. Between 2025–2030, CMDP will deliver critical investment across Water and Wastewater infrastructure throughout the region, including upgrades to Treatment Works, Pumping Stations, and Reservoirs. We are currently seeking an experienced Design Manager to join the team and support the successful delivery of this major programme. The Role Design Managers are project-based and work as part of integrated project teams to deliver the design and engineering aspects of major infrastructure schemes. This may also include supporting major bids and framework opportunities. As a Design Manager, you will be accountable for all design activities relating to a scheme or section of a major project. You will manage multidisciplinary designers, ensuring all design outputs are delivered safely, sustainably, on programme, within budget, and in accordance with technical and governance requirements. You will work within a wider team of Design Managers and report directly to a Principal or Senior Design Manager. At Costain, we believe diverse perspectives drive innovation. If you’re passionate about making a positive impact and believe you can add value to our team, we encourage you to apply — even if you don’t meet every requirement listed. LI-BM1 Key Responsibilities Deliver engineering solutions from initial definition of need through optioneering, solution development, detailed design, and construction support Lead multidisciplinary design teams in the development of wastewater technical solutions Ensure design solutions are affordable, buildable, sustainable, and compliant with project and regulatory requirements Manage design quality control processes and ensure compliance with CDM Regulations Develop collaborative working relationships with clients, construction teams, and supply chain partners Agree and manage design budgets, monitoring performance and forecasting costs to completion Record, monitor, and control design changes to maximise cost efficiency Establish and maintain design programmes and delivery milestones Prepare and manage Design Management Plans and Project Execution Plans Deliver all design stage outputs within agreed timescales and budgets Provide regular progress reporting, including metrics and narrative updates Knowledge, Skills & Experience Essential Academically qualified MEICA Design Engineer Ideally Chartered or working towards Chartership Experience managing design quality control processes Strong multidisciplinary team collaboration skills Ability to deliver designs and tenders to programme, budget, and quality requirements Proactive mindset with the ability to adapt to changing project requirements Understanding of CDM responsibilities and requirements Desirable Experience managing significant design change Knowledge of Electronic Document Management Systems (EDMS) and design workflows Basic legal, contractual, and construction knowledge Ability to influence stakeholders and drive collaborative solutions Experience drafting contractual correspondence Negotiation and team-working skills Qualifications Essential Bachelor’s Degree or Engineering/Management Apprenticeship with relevant industry experience Desirable Chartered Membership of a recognised professional institution (e.g. MICE, IMechE, MCIOB) Project Management or Risk Management training/certification This is an opportunity to be part of one of the UK’s most significant AMP8 infrastructure programmes, delivering long-term improvements to critical water and wastewater assets across the Southern Water region. Join a collaborative environment where innovation, sustainability, and professional development are actively encouraged