For the last few years, the data centre industry has treated grid interconnection as its existential constraint. Queue times stretching into years, transformer shortages, and curtailment clauses buried in power purchase agreements were the conversations that dominated boardrooms and the corridors of every major industry event. But a second bottleneck is slowly emerging and is proving considerably harder to engineer around.
Water rights, the legal entitlement to draw, store and discharge water at a specific location, have quietly moved from due diligence footnote to deal-breaking variable. In the United States alone, more than 40% of planned and existing data centres sit in areas classified as high or extremely high water scarcity.
Arizona has effectively closed new groundwater certificates to hyperscale projects. Virginia has introduced no-net-increase water clauses for new permits. Google’s Lancaster, Ohio facility secured planning approval only after committing to sourcing 100% of its cooling water from non-potable or reclaimed supply. Microsoft’s Mount Pleasant campus in Wisconsin triggered a multi-year hold after regulators demanded comprehensive aquifer studies.
“Water was always an afterthought,” director of research, development and engineering for Ecolab’s global high-tech division, Rob Lowe, told Capacity earlier this year. “When I started in the data centre space six years ago, we would often have conversations with customers after they’d already completed a design or even chosen the equipment and water quality was always an afterthought.”
Ecolab, which works directly with hyperscalers, colocation operators and OEMs to standardise cooling practices, has spent recent years trying to reverse that sequencing – pushing water supply analysis into the earliest stages of site selection rather than treating it as a commissioning-phase concern.
When the aquifer wasn’t in the pro forma
The financial consequences of late-stage water risk discovery are stark. Meta’s Kansas City data centre required more than $500 million in water recycling infrastructure investment to satisfy permitting requirements. That is not a sustainability cost; it is a capital expenditure that was not in the original underwriting model, absorbed mid-project after costs had already been committed.
Legal structures are making this worse. Water rights in the United States operate under fundamentally different frameworks depending on jurisdiction. Prior appropriation states (Colorado, Nevada, Arizona) operate on a seniority system under which newer water users face curtailment first during drought conditions. In practice, this means a hyperscale campus that secures water rights today may find those rights unenforceable within five to 10 years as regional aquifers tighten.
What this produces is a landscape where water permitting timelines now rival electrical interconnection queues and where developers who have spent years building sophisticated power procurement capabilities are discovering that they lack equivalent expertise on the water side.
“Concerns mean it is becoming increasingly difficult to secure permits for building, potentially taking years,” Ann Feng, data centre market director at Veolia, wrote in analysis published by Capacity earlier this month. Veolia, which is targeting more than €1 billion in annual data centre clean technology revenue by 2030, has positioned its integrated water management offer (including reclaimed water sourcing, closed-loop treatment and real-time telemetry) as a direct response to this regulatory tightening. The company’s partnership with Amazon, announced in April, aims to shift AWS facilities onto reclaimed water supply ahead of the company’s 2030 water-positive commitment. At a new Mississippi facility, AWS is planning to transition entirely to recycled water by 2027 using a water-as-a-service model.
The direction of travel is unambiguous. But the scale of incumbent exposure (existing campuses sited in water-stressed geographies on assumptions that no longer hold) is still being mapped.
Community opposition is accelerating the timeline
If regulatory risk alone were insufficient to focus executive attention, the social dimension is now compounding it. As Capacity reported this month, activist Erin Brockovich has launched a public platform cataloguing concerns about data centre development across the United States, receiving more than 4,300 submissions from nearly 1,600 zip codes within weeks of launch. Water concerns account for the single largest category of submissions; above noise, above energy costs, above employment impacts.
The financial scale of what community opposition can do to a development pipeline is no longer theoretical. Projects totalling an estimated $156 billion were delayed or cancelled in 2025 alone as a consequence of local resistance. Amazon has already settled a class action alleging that an AWS facility in Eastern Oregon contributed to nitrate contamination of community drinking water, agreeing to a $20.5 million settlement – a figure that will appear modest against the reputational and regulatory scrutiny it has invited.
None of this is happening in isolation from the regulatory picture. More than 300 data centre-related bills were introduced in 30 US states in the first six weeks of 2026 alone, with a decisive pivot away from tax incentive legislation and towards mandatory water disclosure, permitting requirements for cooling systems, and cumulative environmental impact assessments. Maine is now poised to become the first state to impose a moratorium on new data centre construction, pausing projects until November 2027. Several other states are watching closely.
In April this year, Seattle’s mayor said her administration was “exploring a moratorium on siting new centres” within city limits, after proposed data centre demand collided with mounting pressure on the city’s power system.
The immediate trigger was a Seattle Times report that four companies had approached Seattle City Light about five large-scale facilities with a combined peak demand of 369 megawatts – a third of Seattle’s average daily electricity use. More than 54,000 letters were received by Seattle City Council and the Mayor’s Office.
The issue is not confined to the states. A report published in April found that 84% of proposed UK data centre developments are planned in water-stressed areas. The Environment Agency is not yet factoring the sector into its risk planning, but that gap is unlikely to survive the legislative cycle.
In Asia, Taiwan’s seasonal water-use surcharges for high-volume users came into full effect in 2025. Analysts have projected that total water consumption across the AI supply chain will climb to approximately 1,200 billion litres by 2030, an almost 50% increase from 2023.
Rethinking the site selection calculus
The practical implication for data centre executives is that site selection models built around power availability, land cost and network connectivity are now incomplete. Water security needs to sit alongside those variables from the earliest stage of feasibility analysis.
Some operators are already adjusting. Edged US, which closed nearly $2 billion in financing this year, has integrated waterless cooling across its Atlanta campus portfolio, with the company projecting that its ThermalWorks system will conserve more than 664 million gallons annually compared with conventional facilities once the campus reaches full buildout. The approach reflects a view that eliminating water dependency, rather than managing it, is the only defensible long-term position for sites in constrained geographies.
Others are redirecting capital towards markets where water access is structurally less contested. The Nordic countries, parts of northern Europe and certain Canadian provinces offer a combination of cold ambient temperatures, renewable energy supply and water frameworks that are not yet under the same regulatory pressure.
As Digital Realty’s Lex Coors observed to Capacity in April, the industry has a tendency to apply uniform standards across fundamentally different geographies: “A data centre in Finland should not be measured the same way as one in Spain.” The same logic applies to water.
What is clear is that the window for treating water as a secondary consideration has closed. For developers entering greenfield sites in 2026, water permitting timelines, local hydrological studies and community water impact assessments are now on the critical path alongside grid interconnection and planning consent. For those managing existing campuses in stressed geographies, the question is how quickly cooling architecture can be restructured to reduce municipal water dependency before regulatory frameworks make it compulsory.
The interconnection queue was the problem that reshaped the power procurement strategy. Water rights may do the same for siting strategy, and the organisations building that capability now will not be waiting for the permits to tell them so.
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