The integration of sustainability into water infrastructure projects is no longer optional it is essential for delivering long-term environmental, social, and economic value. However, the implementation of sustainability in green water projects introduces a unique set of complexities that can contribute to significant delays and operational inefficiencies. These challenges include regulatory complexity, innovation adoption barriers, financial limitations, and institutional inertia. Despite the growing emphasis on sustainability in infrastructure, the specific impact of these factors on project timelines remains underexplored in existing literature.

This thesis investigates how sustainability-related complexities affect the timely execution of green water projects and identifies targeted planning strategies to mitigate those impacts. The central research question driving this study is: What planning strategies can help in the successful implementation of Sustainability in Water Projects?

To answer this, the following sub-questions are explored:
1. What are Green Water Projects?
2. How do they differ from traditional projects?
3. What differentiating green factors could result in delays in Green Water Projects?
4. How can these delays be mitigated?

A qualitative multi-phase research approach was adopted to answer these questions, consisting of four key stages: exploratory interviews, literature review, semi-structured expert interviews, and expert feedback workshop with industry stakeholders at Bilfinger Engineering and Consultancy. The exploratory interviews scoped the landscape and helped define "green water projects" in practical terms. The literature review established the conceptual framework, while the semi-structured interviews provided in-depth insights into sustainability-related project delays. The final expert validation tested the practical applicability of the proposed strategies.

The research draws on real-world experiences, including cases involving hydrogen infrastructure, algae-based protein production, and sustainable fuel development, to contextualize the analysis.

The study identifies four core planning solutions tied to the delay drivers:
• Regulatory Uncertainty: Mitigated through early stakeholder alignment and adaptive frameworks like Front-End Loading (FEL) and the Transition Management Framework.
• Technological Novelty: Addressed via iterative testing and feedback using tools such as the Innovation Chasm Strategy and Adaptive Management.
• Financial Feasibility: Enhanced by reducing risk perception through Risk Scoring Matrices, Process Thinking, and Outcome-Based Financing approaches.
• Institutional Capacity: Strengthened through Organizational Learning, Bow Tie Risk Models, and Multilevel Transition Management, which foster resilience and governance alignment.

Building on these findings the study introduces a comprehensive roadmap structured around four interlinked pillars consisting of early stakeholder engagement, bridging the innovation adoption gap, adaptive project management, and institutional alignment with long-term sustainability goals. These pillars are operationalized through a layered approach across strategic, tactical, and operational levels, reflecting the complex, dynamic, and socio-technical nature of sustainability implementation. This multi-level structure enables flexible and adaptive planning that accommodates evolving regulatory, technological, and financial conditions, thereby supporting resilience in project delivery.

A key insight of this research is the redefinition of the traditional Iron Triangle of project management. By incorporating sustainability as a core dimension alongside cost, time, quality, and scope, the study proposes a new paradigm for project planning that aligns with contemporary environmental and social requirements. This reconceptualization allows project teams to evaluate trade-offs more holistically and design solutions that do not sacrifice long-term goals for short-term efficiency. Although the strategies have been tailored to green water projects, they are designed for adaptability and can be applied more broadly to green projects.

Ultimately, the findings serve as a practical guide for project managers and policy stakeholders seeking to overcome sustainability-induced delays. The research contributes to both academic understanding and industry practice by offering an actionable, multi-level planning framework that supports the successful implementation of sustainable infrastructure. By embedding adaptive and transition management principles alongside enhanced governance synchronization, the proposed strategies enable proactive management of uncertainty and institutional alignment, which are essential for scaling sustainable innovations in complex infrastructure projects.