#water

#00179Irrigation water storage pits farmers against communities over shrinking groundwater

As aquifers shrink, storing winter water for summer irrigation splits territories: a minority of irrigating farms gain security while other users and ecosystems fear capture of a common resource. In France the conflict has escalated to court battles and violent protest.

region

#00178Recharge rebound: new water supply enables more extraction unless demand rules exist

Watershed and recharge structures often trigger more irrigation and private pumping rather than restored water tables. Maharashtra's audit of a Rs 9,634 crore watershed program found no significant groundwater improvement in sampled villages while water-hungry crops expanded.

#00177Depleted aquifers and failing rains leave villages without year-round water

Across semi-arid regions, falling water tables and erratic rains leave villages dependent on distant sources or seasonal supplies, driving distress migration and crop failure — from Rajasthan to Brazil's Semiarido and rural Kenya.

3 Solutions 1 Sub-issues

#00176Small single-source communes run out of drinking water in drought

Villages supplied by one well or spring are the first to fail in drought. In summer 2022 more than 100 French communes had drinking water trucked in and over 1,000 took exceptional supply measures; some Pyrenées-Orientales villages later spent months on bottled water.

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#00175Day Zero by decay: leakage and underinvestment collapse urban supply without drought

Some cities run dry not from drought but from decades of underinvestment. Johannesburg loses ~45% of its water to leaks and illegal connections and endures rolling outages even when reservoirs hold water; Mexico City loses ~40%.

#00174Water crises hit the poor hardest through tanker markets and unequal rationing

When piped supply fails, informal tanker markets and rationing shift the burden to low-income households, who pay the highest unit prices for the least water. Chennai's poor got about 30 litres per person per day in 2019 while tanker prices roughly tripled.

#00173Cities in drying climates face recurring Day Zero drinking-water shortfalls

Major cities from Cape Town to Chennai have come within weeks of running dry as droughts lengthen and demand grows. Emergency rationing, tanker dependence, and lost public trust follow, exposing how unprepared urban supply systems are for a drier climate.

9 Solutions 2 Sub-issues

#00118Dump-site locations and drum condition are poorly known

Barrels were logged only approximately when dumped. Their exact positions on a 14,500 km² abyssal plain, their present state of corrosion, and which have already breached and spilled are largely unknown — you cannot manage or monitor what you cannot find.

#00066Water consumption competes with supply exactly where the cooling works best

Evaporative cooling consumes water as its core mechanism (~56 L/day above 30 °C per bloc° unit, against ~24 L/day harvested), and the climates where it works best are typically the most water-stressed — putting public cooling in direct competition with drinking-water supply durin

region

#00060Passive solar throughput (~10 L/m²/day) means collector area scales directly with population served

Solar evaporation yields ~10 L/m²/day outdoors—near the physical ceiling, not an engineering gap. Full domestic use (~50–100 L/person/day) requires 5–10 m² per person; a 10,000-person town needs 5–10 hectares. This bounds the technology to household/hamlet scale, not municipal su

region

#00054Brine discharge from conventional desalination damages the coastal ecosystems these communities depend on

Conventional desalination discharges 58–78% of inlet water as hypersaline brine that raises local salinity and depresses dissolved oxygen, damaging the inshore marine ecosystems coastal fishing communities depend on for food and income.

#00053Decentralized water systems fail after installation from maintenance, spare-parts and ownership gaps

The dominant failure mode of decentralized water infrastructure is not installation — it's what happens in year two and beyond. ~58% of handpumps in sub-Saharan Africa are non-functional at any time, representing $1.2–1.5B in stranded investment over two decades.

#00052Off-grid coastal and island communities cannot sustain conventional desalination for safe drinking water

Coastal, island, and remote communities sit beside seawater but lack safe drinking water. Conventional desalination (RO, thermal) requires reliable power, capital, trained technicians, and supply chains they don't have — and discharges brine that harms local ecosystems.

4 Solutions 2 Sub-issues

Solutions 14

#00219Make reclaimed or non-potable water the default permitted supply for cooling

Condition data-centre cooling permits on treated municipal effluent, brackish groundwater, or industrial process water by default, with potable connection allowed only by explicit exception. Microsoft's San Antonio site reports 79% of consumption from recycled or non-potable sour

city

#00203Long-distance and fossil-aquifer water transfer megaprojects

Pump water hundreds of kilometres or mine non-renewable aquifers to supply cities. A high-risk approach: systemic risk concentrates in a single artery, and fossil-aquifer mining is non-renewable by definition — making both patterns cautionary as much as options.

national

#00202Cloud seeding to enhance precipitation (unproven at decision-relevant scale)

Silver-iodide or hygroscopic seeding of clouds to increase rain or snow. Politically attractive, but the US GAO found estimated effects often statistically indistinguishable from zero, and no drought-scale water yield has been demonstrated anywhere.

region

#00201National water-sobriety plan: withdrawal-reduction targets, reuse rollout and leak funding per basin

A national framework that sets basin-level withdrawal-reduction targets, funds leak repair, unblocks wastewater-reuse permitting and pushes progressive pricing. Delivery depends on municipal-scale mechanisms and sustained funding, not on the announcement itself.

national

#00200Subsidized household rainwater harvesting for water-poor neighborhoods

City-subsidized roof-harvesting kits (first-flush separator, cistern, filters) designed for informal housing and installed with NGO and local-installer training, supplying 5-8 months per year of non-potable and filtered water in suitable climates.

city

#00196Large-scale desalination sized as drought insurance

Seawater reverse osmosis gives cities a rainfall-independent supply. It works when sized against permanent aridification and framed honestly as insurance with flexible operating triggers; it fails financially through drought-panic procurement and rigid take-or-pay contracts.

region

#00190Run water as a public utility with a reinvestment mandate and a standing leak-reduction program

Reform water governance so operating margins are locked into a reinvestment mandate—pipe renewal, leak detection, and repair—rather than extracted as profit or dispersed by weak management. A public regie has a structural advantage in drying climates: it is not penalized by selli

city

#00188Permanent structural demand reduction: turf removal, pricing, rebates and water-culture programs

Retire urban water demand permanently by running demand management as a standing institution with paid turf removal, tiered pricing, appliance and landscape codes, school and business programs, and continuous leak control. Las Vegas cut per-capita use 58% while adding 876,000 res

region

#00186Interconnect small networks, cut leaks and secure backup sources before crisis

Physically link neighboring communal water networks, repair leaking rural pipes, and pre-identify backup sources so no small commune depends on a single vulnerable well or spring. In France, financed via agences de l'eau and départements, typically carried by intercommunal syndic

region

#00185Potable reuse of treated wastewater behind multi-barrier treatment and long acceptance-building

Purify treated wastewater through an advanced multi-barrier train (ultrafiltration, RO, UV/AOP) and return it to drinking supply via aquifer recharge, reservoir blending, or direct injection. Proven since Windhoek's 1968 launch; the binding constraint is public acceptance, not en

city

#00182Transparent emergency demand management: dashboards, escalating tariffs, pressure management and a communicated deadline

Cut urban water demand fast during a supply crisis by combining real-time public dashboards, escalating restriction levels and block tariffs, network pressure management, flow restrictors, and a communicated deadline—with the burden visible and uniform across the city.

city

#00058Coastal fog harvesting with mesh collectors where advection fog is reliable

Where coastal advection fog is dependable, vertical mesh nets passively strain water droplets from wind-driven fog into reservoirs — no energy, no membranes, no seawater intake. Cheap and low-tech, but geographically constrained and historically prone to social/ownership collapse

Aït Baamrane / Mount Boutmezguida, Moroccoregion

#00056Passive solar-thermal interfacial crystallizer using laser-textured superwicking black metal

A femtosecond-laser-textured aluminium panel wicks seawater uphill across its face, absorbs ~92% of sunlight to evaporate it, and uses the coffee-ring effect plus salt creeping to push crystallised salt to the panel edges — self-cleaning, no membranes, no chemicals, no electricit

region

#00055Professionalized, results-based maintenance service paid for by uptime (not community self-management)

Replace volunteer committees with a professional maintenance company on a performance contract: hotline, guaranteed repair times (~3 days), preventive maintenance, and a stocked parts supply chain — funded by pooled mobile-money subscriptions and results-based payments tied to up

Kitui County, Kenyaregion