“Resilience requires more than technology. It requires rules, institutions, and capital to carry solutions from pilots to global scale.” 

Technology can push boundaries. Communities can demonstrate resilience. But without enabling policy and the financial flows to match, adaptation and mitigation strategies in water reuse and desalination remain trapped at the margins. This is where finance and governance become the real levers of transformation. 

The Capital Challenge 

According to the World Bank (2025), the world faces an annual spending shortfall of USD 131–140 billion for water and sanitation infrastructure: nearly double current public funding levels. To close decades of underinvestment and meet the Sustainable Development Goals, the World Bank estimates that USD 7 trillion will be needed by 2030 (World Bank, 2024). 

The OECD (2025) warns the financing gap could balloon to USD 6.4 trillion by 2030 if reforms stall, underscoring the need for systemic change. Meanwhile, development banks approved USD 19.6 billion in water projects in mid-2025, with USD 14.4 billion directed toward low- and middle-income countries, a sign of growing momentum but still far below what is required. 

Reuse and desalination remain underfunded. Globally, reuse accounts for just 8 percent of total water use (UN-Water, 2024), while desalination supplies only about 1 percent of demand (World Bank, 2025). Scaling these solutions demands not just technology, but new approaches to finance and policy. 

Policy as an Enabler 

Where reuse and desalination have reached scale, policy has laid the foundation: 

• California has embedded long-term reuse into law, targeting up to 60 percent reuse by 2040, supported by multi-billion-dollar programs. 

• Israel operates under a centralized national water authority, reusing over 85 percent of treated wastewater for agriculture. 

• Spain integrates desalination into drought contingency plans, ensuring facilities remain financially viable in both wet and dry years. 

• The Gulf states have created integrated regulatory ecosystems that guarantee offtake for independent water producers, reducing risk and attracting global capital. 

Policy does more than regulate. It creates stable conditions where investors can commit with confidence. 

Financing Models That Work 

Scaling water reuse and desalination requires models that reduce risk and accelerate adoption: 

• Public-Private Partnerships (PPPs): Widely used in the Middle East, PPPs provide stable contracts and transfer risk while enabling rapid expansion of desalination capacity. 

• Green Bonds and Climate Finance: Global green bond issuances exceeded USD 500 billion in 2022, and a growing share is being directed to water resilience (World Bank, 2025). 

• Blended Finance: By combining concessional and private capital, blended models are unlocking projects in higher-risk regions, including Sub-Saharan Africa. 

• Outcome-based Financing: New frameworks highlighted by the OECD (2025) stress long-term outcomes and balanced risk-sharing, making water projects more attractive to investors. 

The barrier is not the lack of global capital, but the perception that water is fragmented and risky. Policy clarity and financing innovation can change that. 

Case Studies: Policy Meets Capital 

• Abu Dhabi: Through its regulatory ecosystem and the Mohamed Bin Zayed Water Initiative, Abu Dhabi has pioneered frameworks that reduce investor risk while catalyzing frontier innovation, including the global XPrize Water Scarcity Challenge. 

• Chile: Legal reforms to its Water Code are opening space for desalination and reuse, with PPPs bringing private investment into municipal projects. 

• Brazil: The Brazilian Association of Sanitation and Environmental Engineering (ABES) is shaping financing frameworks for urban reuse, supported by development banks. 

• South Africa: The Development Bank of Southern Africa is piloting financing structures that combine domestic and international climate funds to expand reuse in drought-stricken regions. 

Each case shows how policy direction and financial innovation can turn ambition into delivery. 

Global Coordination and Accountability 

Scaling adaptation is not only about funding pipelines. It is also about ensuring accountability and equity. Organizations like the 2030 Water Resources Group (World Bank) and the CEO Water Mandate (Pacific Institute) are working to align public and private stakeholders, while UN-Water’s 2024 monitoring report provides the global benchmarks needed to measure progress. 

Equity remains critical. Without safeguards, investment risks favoring industrial or urban users over vulnerable communities. Social equity must remain central to financing frameworks. 

The Reykjavík Message 

The story of reuse and desalination is no longer just about technology. It is about how governance, capital, and accountability can accelerate solutions at the scale the world needs. 

As the IDRA Reykjavík Summit 2025 convenes leaders from governments, finance, and industry, one message is clear: 
Adaptation and mitigation in water will not scale without enabling policy and financial innovation. 

If the world is to move from 8 percent reuse to 80 percent, from pilot desalination plants to national resilience, it will be because rules and resources aligned with science and innovation. Reykjavík is where those alignments begin to take shape.