Desalination could bypass rather than resolve upstream water leverage, but the gap between coast and hinterland is vast

Solar-powered desalination could make downstream nations independent of upstream dam control by providing an alternative freshwater source. This “sidestep” logic — growing the pie rather than fighting over the existing one — parallels land readjustment’s approach. But rivers provide sediment, fisheries, transport, and ecosystem services that desalinated water cannot replicate, and inland populations are hardest to reach.

Explanandum

Can technology solve a problem that diplomacy has failed to address? If upstream leverage is structurally asymmetric and international governance has no enforcement mechanism, is the only solution to make the resource less scarce?

Substance

Tabarrok argues that since upstream nations will never voluntarily constrain themselves, the solution is to reduce downstream dependence. Falling solar costs remove the main economic barrier to desalination (energy), and water storage is easier than electricity storage, so solar intermittency matters less. All of China’s downstream neighbours except Laos have coastlines.

The logic is appealing: rather than trying to force cooperation from a position of weakness, make cooperation unnecessary. This parallels land readjustment (grow property value so everyone benefits), better competition metrics (redefine the metric so the right question gets asked), and the general positive-sum approach of Works in Progress as a publication.

But the gaps are significant. Desalinated water arrives at the coast; the populations most at risk are inland farmers in Bangladesh, the Mekong Delta, and Indian states along the Brahmaputra. Infrastructure to pipe desalinated water hundreds of kilometres inland would be enormous, expensive, and decades in the making. Brine waste damages marine ecosystems at scale. And rivers provide sediment (critical for delta agriculture), fisheries, transport, and ecosystem services that no amount of freshwater replacement addresses.

Supports

• Saudi Arabia and Israel already operate large-scale desalination, proving feasibility
• Solar and membrane costs are falling on well-documented curves
• The logic of technological bypass has precedents: air travel making railway monopolies less relevant, mobile telephony making landline monopolies less relevant

Challenges

• Bangladesh’s existential threat is from changed sediment flows and flood patterns, not just water volume
• Inland agricultural populations can’t be served from coastal plants without massive new infrastructure
• Brine disposal at the scale required would significantly harm marine ecosystems
• China would continue diverting water regardless of downstream desalination — the domestic water crisis drives policy independently

Open Questions

• Is the desalination proposal better understood as a bargaining chip (downstream nations building alternatives strengthens their negotiating position) than a literal replacement for river water?
• Could distributed small-scale desalination (as tested in Mexico) complement rather than replace river systems?

Source Context

Central to the Tabarrok article’s proposed solution. Critiqued in discussion as underestimating the coast-to-hinterland gap and the non-volumetric functions of rivers.