The Water Finance Question the World Can No Longer Ignore, IWMI Warns

September 2026 — From Cyclone Ditwah’s devastation in Sri Lanka to catastrophic flash floods in Nepal and Tibet, successive natural disasters have laid bare the cost of underinvesting in water resilience, according to the International Water Management Institute (IWMI), which is calling for the 2026 UN Water Conference in Abu Dhabi to close a water finance gap now estimated at $200 billion annually and potentially tripling by 2030.

Background

On November 28, 2025, Cyclone Ditwah moved across Sri Lanka, triggering one of the country’s most severe weather emergencies in decades. After forming as a deep depression in the Bay of Bengal, the storm made landfall along the eastern coast before moving inland, inundating low-lying areas and overwhelming rivers across the Central, North Central and North Western provinces. Catastrophic flooding and landslides followed, with some districts receiving more than 300 mm of rainfall, agricultural fields deluged, and planting seasons dismantled. Approximately 2.2 million people were affected across all 25 districts, with many evacuated from their homes and fields.

More recently, on August 26, 2026, a flash flood in Nepal and Tibet caused catastrophic consequences across the northern Himalaya. Heavy monsoon rains overwhelmed river systems already swollen by glacial melt, sending floodwaters through valleys and communities with little warning. Critical infrastructure suffered severe damage, agricultural land was buried under sediment, and thousands remained missing. For a country where nearly 60% of the population depends on agriculture and mountain communities have minimal buffer against such shocks, the losses extended far beyond what any disaster-response figure can capture.

IWMI’s Role in Disaster Response

For years, IWMI has helped governments put climate and hydrological models to work in disaster response. During Cyclone Ditwah, IWMI provided technical support to the Emergency Operations Centre of the Sri Lankan Disaster Management Centre, which operationalized IWMI’s AWARE platform for flood forecasting and monitoring, while IWMI researchers provided daily integrated satellite mapping of flood inundation, tracking country-level exposure on populations, buildings and agriculture. Within 24 hours of the disaster, IWMI developed a digital tool to process hard-copy rescue-related police reports into digital formats, helping Sri Lankan authorities speed up on-the-ground rescue efforts. In Nepal, IWMI remains committed to providing technical assistance to authorities supporting immediate post-disaster risk management priorities.

What the Science Says

The IPCC’s Sixth Assessment Report is unequivocal that climate change is fundamentally altering the global water cycle: precipitation is becoming more intense and erratic, glaciers are in accelerating retreat, and droughts and floods will grow more frequent and severe. Globally, over three billion people currently experience severe water scarcity for at least one month a year, and the IPCC is clear that water is the primary medium through which most people will experience the impacts of climate change.

This is no longer a distant risk — it is present reality for countries like Sri Lanka and Nepal, carrying a hefty price tag. The IPCC estimates that water-related climate risks will require adaptation investment in the hundreds of billions annually, yet investment is not flowing at anything close to the required scale.

Water Financing Remains a Missing Piece

Water is sector-agnostic, connecting rainfall, groundwater, agriculture, energy, ecosystems and human health into a single interdependent system — but it is also deeply political, heavily subsidized, difficult to price, and governed by overlapping mandates that make it hard for private capital to invest. By 2030, global demand for water is projected to outpace supply by 40%.

IWMI identifies four conditions needed to build the scaffolding for water finance to flow:

Bankable value. Unlike the energy transition, water lacks a unit of account and revenue mechanism comparable to the megawatt-hour or the tradeable carbon ton. Fewer than 1% of major corporations fully understand their water dependencies, only 26% of Fortune 500 companies have freshwater consumption targets, and while 44% of companies disclosing to the Carbon Disclosure Project report substantial water-related challenges, those risks don’t appear on balance sheets in any standardized way.

A clear political signal. Just as the 2015 Paris Agreement repriced risk across energy markets, water has had no equivalent moment. IWMI frames the 2026 UN Water Conference as the best opportunity to generate that signal through measurable, financed commitments that multilateral development banks and national governments can translate into lending mandates.

Institutional architecture. In 2024, multilateral development banks hit a record $137 billion in total climate finance, with clean electricity alone receiving $25.6 billion from MDBs to developing countries. By contrast, all MDB water commitments in 2024 totaled only $19.6 billion, with water receiving roughly 3% to 8% of tracked global climate finance. In Africa, only 9% of water investment in developing countries is private, compared to 45% in power and 87% in telecoms — a gap linked partly to governments spending around 0.5% of GDP on water, a figure that has barely shifted despite the sector’s centrality to development outcomes. Some MDBs have taken steps, including the Asian Development Bank’s Water Financing Partnership Facility, which has mobilized $9.45 billion across 20 countries since 2006 — meaningful but insufficient against a $200 billion annual gap. IWMI argues water still lacks a global institutional anchor equivalent to the International Renewable Energy Agency (IRENA) or the Green Climate Fund.

The enabling environment. Fragmented project pipelines, weak off-takers, insufficient hydrological data and weak policy frameworks work against cost recovery, slowing or blocking investment even when innovative financial instruments exist. Building policy coherence, regulatory frameworks and data infrastructure is less visible work, but essential — and unlikely to attract private investment on its own, meaning bilateral and multilateral actors must lead.

Recent Developments Offer Cautious Optimism

There are signs the political architecture surrounding water is beginning to shift. At COP29 in Baku, Azerbaijan in November 2024, 57 governments and 25 international organizations signed the Declaration on Water for Climate Action — the first dedicated water declaration at a climate COP — launching the Baku Dialogue on Water for Climate Action, a COP-to-COP platform designed to maintain continuity on water between climate conferences. Its first high-level session took place at COP30 in Belém, Brazil, in 2025.

At the June Climate Meetings in Bonn in mid-2025 (SB62), water was explicitly recognized as a sector under the adaptation finance tracking framework — a technical but significant step creating a foundation for measuring and holding countries accountable for water adaptation spending for the first time.

In September 2026, IWMI and the IPCC will hold the first-ever co-sponsored Expert Meeting to advance the science of water in climate change, gathering around 60 leading experts in Colombo, Sri Lanka, to help shape the evidence for the IPCC’s Seventh Assessment Report by spotlighting water’s role in climate adaptation, resilience and risk.

IWMI also points to the Fund for Responding to Loss and Damage, established at COP28 in Dubai in 2023, noting that water-related disasters such as those in Sri Lanka and Nepal account for the vast majority of qualifying loss and damage events — meaning water must be central to how the Fund is operationalized and disbursed, not treated as a separate conversation.

A Call to Action for the 2026 UN Water Conference

IWMI describes the 2026 UN Water Conference in Abu Dhabi this December as a significant opportunity for the water sector — an implementation conference opening a window for parties to be newly ambitious about what will actually be financed and delivered. The science is clear, decision-support tools are tested, and the water finance gap has a number against it. What remains uncertain, IWMI argues, is the political will to treat water as the climate infrastructure it has always been.

Conclusion

The farmers in Sri Lanka who lost a planting season and vital income to Cyclone Ditwah, and the communities in Nepal still accounting for what was swept away just weeks ago, did not cause the water finance gap — they are absorbing its consequences. As IWMI frames it, the finance built for resilience, adaptation and loss and damage must be built with these communities in mind, both now and for the future, making the 2026 UN Water Conference a critical test of whether political momentum can finally translate into the capital mobilization water security demands.