> For the complete documentation index, see [llms.txt](https://docs.therisk.global/organization/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.therisk.global/organization/model/scenarios/urban-flood.md). # Urban flood Urban flood: the coupled risk across water, energy, infrastructure and health, and the applied response of the programme pillars, as a teaching context of the Nexus model. **Where this fits:** water, energy, infrastructure and health · Labs, Foundry, Nexus Universe, Nexus Standards and Risk Academy · the Nexus Consortium · the whole programme year · teaching context. > Flooded streets take out substations, pumping stations and clinic access together; drinking water fails when power does. **In brief.** In this teaching context water and infrastructure are hit first. 4 of the six sectors are in play through 6 of the fifteen relations, a coupling of 0.46 of the whole system, and the teaching cascade amplifies the initial shock ×2.06. On the response side, 5 of the six pillars apply, with 11 of the eighteen handoffs in play and 8 feedback loops closed. All sector values are **teaching values for a typical city-region, not measurements for any place**; the applications are illustrative and the cited values are published benchmarks, not forecasts.
Two hexagons. Left, coupled risk: in an urban flood, water and infrastructure are hit first; four of the six sectors (water, energy, infrastructure, health) are in play through six of the fifteen relations, and the teaching cascade amplifies the initial shock 2.06 times. Right, applied response: five of the six programme pillars apply to the context (Labs, Foundry, Universe, Standards, Academy), with eleven of the eighteen handoffs between them in play; each pillar answers for one measure, and the cited return on resilient infrastructure is about four to one. Underneath, the eight phases of the programme year in which handoffs happen.

Coupled risk, applied response: urban flood. The same model and values as the GCRI, GRF and GRA home pages. Left: teaching values for a typical city-region, not measurements. Right: illustrative applications and the measure each pillar answers for; values are published benchmarks (World Bank, Lifelines, 2019; Global Commission on Adaptation, Adapt Now, 2019), not forecasts. Source: the sectors and pillars model published on the GCRI, GRF and GRA home pages, vendored and hash-pinned in tools/figures/vendor/nexus-model. As of 2026-10-21.

Figure data (text alternative) | Element | Kind | Description | Value | | ------------------------- | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- | | Water and Energy | Relation in play | Water to energy: cooling water and hydropower (0.6); Energy to water: pumping and treatment (0.5) | 0.55 | | Water and Infrastructure | Relation in play | Water to infrastructure: erosion and flood damage (0.3); Infrastructure to water: pipes, dams and treatment works (0.6) | 0.45 | | Water and Health | Relation in play | Water to health: drinking water and sanitation (0.7); Health to water: utility workforce (0.2) | 0.45 | | Energy and Infrastructure | Relation in play | Energy to infrastructure: power for transport and telecoms (0.8); Infrastructure to energy: transmission and fuel logistics (0.6) | 0.70 | | Energy and Health | Relation in play | Energy to health: hospital power (0.5); Health to energy: grid workforce (0.2) | 0.35 | | Infrastructure and Health | Relation in play | Infrastructure to health: access to care (0.5); Health to infrastructure: workforce for operations (0.3) | 0.40 | | Water | Sector | first hit, then depends on infrastructure for pipes, dams and treatment works | stress 0.86 | | Energy | Sector | depends on water for cooling water and hydropower | stress 0.37 | | Infrastructure | Sector | first hit, then depends on energy for power for transport and telecoms | stress 0.83 | | Food | Sector | outside this context | – | | Health | Sector | depends on water for drinking water and sanitation | stress 0.41 | | Biodiversity | Sector | outside this context | – | | Amplification | Cascade | Shock 0.6 at Water and Infrastructure, gain 0.35, 4 rounds; coupling 0.46 of the total | ×2.06 | | F01 | Handoff in play | Universe to Foundry: Admitted mission becomes a cycle project with a decision case | Readiness preparation | | F02 | Handoff in play | Foundry to Universe: Core Build Report and go or no-go evidence | Controlled build | | F03 | Handoff | Foundry to Reports: Sealed observations and indicator series behind a profile | Closeout | | F04 | Handoff | Universe to Reports: After-action and scenario findings for chapters 10 and 13 | After-action review | | F05 | Handoff | Foundry to Reports: National Portfolio movement for chapter 11 | After-action review | | F06 | Handoff | Reports to Standards: Method and correction findings as change proposals | Correction | | F07 | Handoff in play | Universe to Standards: Docket items that need a standard or a profile | Docket review | | F08 | Handoff in play | Standards to Foundry: Composed mission profiles and national adoption records | Readiness preparation | | F09 | Handoff in play | Standards to Academy: Each adopted standard or profile becomes a course module | Renewal | | F10 | Handoff in play | Universe to Academy: Assessed cycle tasks become completion evidence | Closeout | | F11 | Handoff in play | Academy to Universe: Qualified participants for the next cycle's roles | Renewal | | F12 | Handoff | Reports to Universe: Q4 synthesis informs the next-year mandate | Renewal | | F13 | Handoff in play | Foundry to Standards: Validation and monitoring evidence for conformance review | Controlled build | | F14 | Handoff in play | Foundry to Academy: Each system's rooms become a learning-by-doing course | Planning | | R1 | Handoff | Standards to Reports: Applied in editions | Around the ring | | R2 | Handoff | Reports to Academy: Taught in the open | Around the ring | | R3 | Handoff in play | Academy to Labs: Questions become experiments | Around the ring | | R4 | Handoff in play | Labs to Foundry: Tested prototypes are built | Around the ring | | Labs | Pillar | Flood-depth nowcast from rain gauges and terrain | Warning lead time ↑ 30% | | Foundry | Pillar | City twin links substations, pumps and clinics to flood depth | Lifelines modelled ↑ | | Universe | Pillar | Exercise: keep water and power running through a 1-in-100 flood | Hours to restore ↓ | | Standards | Pillar | Shared asset records so utilities exchange outage data | Agencies sharing records ↑ | | Reports | Pillar | City flood profile of exposed lifelines | Assets profiled ↑ $390B | | Academy | Pillar | Course for utility and emergency operators | Operators qualified ↑ | | Value at risk | Cited value | At least, by households and firms in low- and middle-income countries to infrastructure disruptions. World Bank, Lifelines, 2019 | $390B a year at least, in infrastructure disruption costs to households and firms in low- and middle-income countries | | Return on resilience | Cited value | Net benefit of more resilient infrastructure in developing countries, over the life of the assets. World Bank, Lifelines, 2019 | 4 : 1 benefit to cost | | Avoided loss | Cited value | With 24 hours' warning of a coming storm or heatwave. Global Commission on Adaptation, Adapt Now, 2019 | 30% less damage with 24 hours' warning of a storm or heatwave | | Planning | Phase (Q1, G0) | F14 Each system's rooms become a learning-by-doing course | 1 handoff(s) | | Readiness preparation | Phase (Q2, G2) | F01 Admitted mission becomes a cycle project with a decision case; F08 Composed mission profiles and national adoption records | 2 handoff(s) | | Controlled build | Phase (Q2, G3) | F02 Core Build Report and go or no-go evidence; F13 Validation and monitoring evidence for conformance review | 2 handoff(s) | | Closeout | Phase (Q3, G5) | F03 Sealed observations and indicator series behind a profile; F10 Assessed cycle tasks become completion evidence | 2 handoff(s) | | After-action review | Phase (Q3) | F04 After-action and scenario findings for chapters 10 and 13; F05 National Portfolio movement for chapter 11 | 2 handoff(s) | | Correction | Phase (Q4) | F06 Method and correction findings as change proposals | 1 handoff(s) | | Docket review | Phase (Q4) | F07 Docket items that need a standard or a profile | 1 handoff(s) | | Renewal | Phase (Q4, G7) | F09 Each adopted standard or profile becomes a course module; F11 Qualified participants for the next cycle's roles; F12 Q4 synthesis informs the next-year mandate | 3 handoff(s) |
## Coupled risk | Sector | In this context | Stress after four rounds | | --------------------------------------------------------------- | ----------------------------------------------------------------------------- | ------------------------ | | [Water](/organization/model/sectors/water.md) | Hit first; then depends on infrastructure for pipes, dams and treatment works | 0.86 | | [Energy](/organization/model/sectors/energy.md) | Depends on water for cooling water and hydropower | 0.37 | | [Infrastructure](/organization/model/sectors/infrastructure.md) | Hit first; then depends on energy for power for transport and telecoms | 0.83 | | [Food](/organization/model/sectors/food.md) | Outside this context | – | | [Health](/organization/model/sectors/health.md) | Depends on water for drinking water and sanitation | 0.41 | | [Biodiversity](/organization/model/sectors/biodiversity.md) | Outside this context | – | Amplification ×2.06; 6 of the 15 relations in play; coupling 0.46 of the total. Teaching values for a typical city-region, not measurements for any place. Coupling is the summed strength of the relations in play, as a share of all fifteen. **What it means for a study.** A study of urban flood that maps flood depth alone misses most of the harm. Water and infrastructure are hit first, but health is reached through drinking water and access to care, and energy through pumping and treatment. The assets to observe together are the substations, pumping stations, treatment works and clinics in the flood footprint, and the dependencies between them. ## Applied response | Pillar | Illustrative application | Measure it answers for | Better when | Sectors served | | ----------------------------------------------------------------- | --------------------------------------------------------------- | ------------------------ | ----------- | ------------------------------------- | | [Labs](/organization/programme/labs.md) (applied) | Flood-depth nowcast from rain gauges and terrain | Warning lead time | higher | Water, Infrastructure | | [Foundry](/organization/programme/foundry.md) (applied) | City twin links substations, pumps and clinics to flood depth | Lifelines modelled | higher | Water, Energy, Infrastructure, Health | | [Nexus Universe](/organization/programme/universe.md) (applied) | Exercise: keep water and power running through a 1-in-100 flood | Hours to restore | lower | Water, Energy, Health | | [Nexus Standards](/organization/programme/standards.md) (applied) | Shared asset records so utilities exchange outage data | Agencies sharing records | higher | Water, Energy, Infrastructure | | [Nexus Reports](/organization/programme/reports.md) | City flood profile of exposed lifelines | Assets profiled | higher | Infrastructure | | [Risk Academy](/organization/programme/academy.md) (applied) | Course for utility and emergency operators | Operators qualified | higher | Water, Energy, Health | **What it means for a response.** The response is built around restoring lifelines in the right order. Labs shortens warning lead time; the Foundry links the city's assets to flood depth in one model; Universe exercises a 1-in-100 flood with the operators who would act; Standards gives utilities shared asset records so they can exchange outage data; Academy qualifies the operators. In every case the responsible government, operator or licensed institution decides and acts; the programme informs that decision. ## Published benchmarks | Slot | Value | What it measures | Source | | -------------------- | --------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------- | | Value at risk | $390B a year at least, in infrastructure disruption costs to households and firms in low- and middle-income countries | At least, by households and firms in low- and middle-income countries to infrastructure disruptions | [World Bank, Lifelines, 2019](https://openknowledge.worldbank.org/handle/10986/31805) | | Return on resilience | 4 : 1 benefit to cost | Net benefit of more resilient infrastructure in developing countries, over the life of the assets | [World Bank, Lifelines, 2019](https://openknowledge.worldbank.org/handle/10986/31805) | | Avoided loss | 30% less damage with 24 hours' warning of a storm or heatwave | With 24 hours' warning of a coming storm or heatwave | [Global Commission on Adaptation, Adapt Now, 2019](https://gca.org/reports/adapt-now-a-global-call-for-leadership-on-climate-resilience/) | Each value is international evidence with its own scope, cited on the same line. None is a forecast for any project or place. See [Method and limits](/organization/model/method-and-limits.md) for how to read the values precisely. ## On the public sites The same context, with the same values, is shown on the [GCRI home](https://therisk.global/) page. ## Related pages [All scenarios](/organization/model/scenarios.md) · [Coupled risk](/organization/model/coupled-risk.md) · [Applied response](/organization/model/applied-response.md) · [Water](/organization/model/sectors/water.md) · [Energy](/organization/model/sectors/energy.md) · [Infrastructure](/organization/model/sectors/infrastructure.md) · [Health](/organization/model/sectors/health.md) ## Sources * World Bank, Lifelines, 2019. * Global Commission on Adaptation, Adapt Now, 2019. * The model data: the "Coupled risk, applied response" section of the [GCRI home page](https://therisk.global/). --- # Agent Instructions This documentation is published with GitBook. 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