The Global Risks Index
NXS-GRX · GRX-IDX-WAT · VUL Human and systems vulnerability

Water security risk index

0-10 index of water security risk combining scarcity and stress, WASH access, water quality and transboundary dependence; geometric so that good access does not offset severe scarcity.

Page GRX-IDX-WATEdition Baseline Edition 2026Evidence close 2026-09-30Indicator Standard IDX.WAT.stress.water_security_riskValues not yet publishedSnapshot 31a753f76
FIG 1 · Method card
Aggregation

geometric

equal weights · floor 0.1 where geometric

Uncertainty

1,000 draws

normalisation, weights, aggregation, imputation

Structure

4 components

11 leaf indicators

Coverage

75% minimum

modelled share ≤ 20%

From the Indicator Standard definition of this index.
11
leaf indicators
4
components
1,000
Monte Carlo draws
6
series read it
01Construction

From indicators to the composite

The water dimension of a place profile; each sub-index stays visible beside the index.

computation
How Water security risk is computed
Graph18 nodes
Graph
01Indicators
02Sub-indices
03Domain index
04Pillar
05Composite
100%
List
  1. Level of water stress
    Indicator · IND · %
    Total freshwater withdrawn by all sectors as a percentage of total renewable freshwater resources after subtracting environmental flow requirements.
  2. Total renewable freshwater resources per capita
    Indicator · IND · m3/a/{person}
    Long-term average internal and external renewable surface and groundwater resources per resident, in cubic metres per year.
  3. Groundwater storage decline
    Indicator · IND · mm/a
    Trend in terrestrial groundwater storage over at least 15 years, in millimetres of equivalent water height per year (positive = decline), from satellite gravimetry with modelled soil-moisture and surface-water storage removed.
  4. Water-use efficiency
    Indicator · IND · [USD]/m3
    Gross value added of agriculture, industry and services per cubic metre of water withdrawn by those sectors, at constant 2015 US dollars, weighted by each sector's share of withdrawals; its change over time is the SDG target measure.
  5. Population using safely managed drinking water
    Indicator · IND · %
    Share of the population using an improved drinking-water source located on premises, available when needed and free from faecal and priority chemical contamination.
  6. Population using safely managed sanitation
    Indicator · IND · %
    Share of the population using an improved sanitation facility not shared with other households, whose excreta are safely disposed of in situ or treated off site.
  7. Population with basic hand-washing facilities
    Indicator · IND · %
    Share of the population with a hand-washing facility with soap and water available at home.
  8. Water bodies with good ambient water quality
    Indicator · IND · %
    Share of monitored river, lake and groundwater bodies whose measured oxygen, salinity, nitrogen, phosphorus and acidity meet national good-quality targets.
  9. Wastewater flows safely treated
    Indicator · IND · %
    Share of domestic and industrial wastewater flows that are treated to a level meeting national or local standards before discharge.
  10. Dependency ratio on external renewable water
    Indicator · IND · %
    Share of total renewable water resources that originates outside the country, as inflow from upstream countries or shared aquifers.
  11. Transboundary basin area with operational cooperation
    Indicator · IND · %
    Share of the country's transboundary river, lake and aquifer basin area covered by an arrangement for water cooperation that is operational.
  12. Water scarcity and stress sub-index
    Sub-index · SUB · w 2 · 40.0%
    Composite of the level of water stress, renewable water per capita, groundwater storage decline and water-use efficiency.
  13. Drinking water, sanitation and hygiene access sub-index
    Sub-index · SUB · w 1 · 20.0%
    Composite of safely managed drinking water, safely managed sanitation and basic hand-washing coverage.
  14. Water quality sub-index
    Sub-index · SUB · w 1 · 20.0%
    Composite of the share of water bodies with good ambient quality and the share of wastewater safely treated.
  15. Transboundary water dependence sub-index
    Sub-index · SUB · w 1 · 20.0%
    Composite of the external water dependency ratio and the share of transboundary basin area under operational cooperation.
  16. Water security risk index
    Domain index · IDX · geometric
    0-10 index of water security risk combining scarcity and stress, WASH access, water quality and transboundary dependence; geometric so that good access does not offset severe scarcity.
  17. Human and systems vulnerability
    Pillar · PILLAR · 8 indices
    How susceptible are people, livelihoods, ecosystems and essential systems to harm when a shock arrives?
  18. NXS-GRX Composite Risk
    Composite · COMPOSITE · four pillars
    Composite = (HTE × VUL × MSF × LCC)^(1/4), each pillar on 0–10 floored at 0.1; pillar = expert-weighted geometric mean of its domain indices
Not runIn progressDone
FIG 2. 11 indicators, 4 components, real Indicator Standard weights (the bar under each node is its share). Select a node to trace what it feeds and what feeds it; Simulate run plays the computation in order.
02Simulator

Run this index's own aggregation

Set each component, change the aggregation or the weight uncertainty, and watch the interval, the class probability and each component's contribution respond.

FIG 3 · Simulator: aggregate water security risk on your numbers
Components (0 to 10)
3.0
5.0
7.0
4.0
25
1
–
runs in your browser
Contribution of each component (leave one out)
Simulator: the index's published aggregation run on numbers you set, with 1,000 draws over weights and aggregation. The slider positions are starting points for the explainer, not NXS-GRX (canonical data, provenance and risk) values.
03Method

Treatment, normalisation, weighting, aggregation, uncertainty

Treatment
WINSORISE
Outlier rule
|skew| > 2, kurtosis > 3.5
Normalisation
MIN_MAX
Imputation
NONE
Coverage minimum
75% of components
Modelled share cap
20% of weight
Weighting
equal
Aggregation
geometric
Scale
0 to 10
Uncertainty
1,000 Monte Carlo runs over normalisation, weights, aggregation, imputation
Framework basis
SDG 6; UN-Water water security framing; OECD/JRC Handbook (2008)
Very low0.0 to < 2.0
Low2.0 to < 3.5
Medium3.5 to < 5.0
High5.0 to < 6.5
Very high6.5 to 10.0
04Components

4 components, 11 indicators

Water scarcity and stress sub-index w 2

Composite of the level of water stress, renewable water per capita, groundwater storage decline and water-use efficiency.

IndicatorUnitEvidenceSourcesShare
Level of water stressIND.WAT.stress.water_stress%Class Bfao-aquastat, un-sdg-database, wb-wdi44.4%
Total renewable freshwater resources per capitaIND.WAT.stress.renewable_water.pcm3/a/{person}Class Bfao-aquastat, wb-wdi22.2%
Groundwater storage declineIND.WAT.stress.groundwater_depletionmm/aClass Cnasa-grace-fo, igrac-ggis, national-groundwater-monitoring22.2%
Water-use efficiencyIND.WAT.stress.water_use_efficiency[USD]/m3Class Bfao-aquastat, un-sdg-database, wb-wdi11.1%

Drinking water, sanitation and hygiene access sub-index w 1

Composite of safely managed drinking water, safely managed sanitation and basic hand-washing coverage.

IndicatorUnitEvidenceSourcesShare
Population using safely managed drinking waterIND.WAT.access.safely_managed_drinking_water.share%Class Bwho-unicef-jmp, wb-wdi33.3%
Population using safely managed sanitationIND.WAT.access.safely_managed_sanitation.share%Class Bwho-unicef-jmp, wb-wdi33.3%
Population with basic hand-washing facilitiesIND.WAT.access.basic_handwashing.share%Class Bwho-unicef-jmp, wb-wdi33.3%

Water quality sub-index w 1

Composite of the share of water bodies with good ambient quality and the share of wastewater safely treated.

IndicatorUnitEvidenceSourcesShare
Water bodies with good ambient water qualityIND.WAT.quality.good_ambient_water_quality.share%Class Bunep-gems-water, un-sdg-database50.0%
Wastewater flows safely treatedIND.WAT.quality.wastewater_safely_treated.share%Class Bwho-un-habitat-wastewater, un-sdg-database50.0%

Transboundary water dependence sub-index w 1

Composite of the external water dependency ratio and the share of transboundary basin area under operational cooperation.

IndicatorUnitEvidenceSourcesShare
Dependency ratio on external renewable waterIND.WAT.dependence.external_water_dependency%Class Bfao-aquastat66.7%
Transboundary basin area with operational cooperationIND.WAT.dependence.transboundary_cooperation.share%Class Bunece-unesco-sdg652, un-sdg-database33.3%
05Domain

Water

Water availability, stress, access, quality and transboundary dependence.

Sub-domainIndicators
Water stress5
Drinking water and sanitation4
Water quality2
Transboundary dependence2

Anchor frameworks (pillar structure and definitions only): SDG 6; FAO AQUASTAT.

06Indicators

All 13 water indicators

FIG 4 · Indicators in scope, by domain and sub-domain
WAT · 13
Area is the number of indicator definitions; colour is the pillar the domain feeds (Macroeconomy and Space feed through their indices). Select a block to filter the table.
IndicatorDomainSub-domainComponentUnitLevelsCrosswalks
Level of water stressIND.WAT.stress.water_stressWATWater stresshazard%COUNTRY, ADM1SDG 6.4.2 WB_WDI ER.H2O.FWST.ZS
Baseline water stress score (sub-basin)IND.WAT.stress.baseline_water_stressWATWater stresshazard{score}COUNTRY, ADM1, CITY, GRID, SITE, PORTFOLIO
Total renewable freshwater resources per capitaIND.WAT.stress.renewable_water.pcWATWater stresshazardm3/a/{person}COUNTRYWB_WDI ER.H2O.INTR.PC
Groundwater storage declineIND.WAT.stress.groundwater_depletionWATWater stresshazardmm/aCOUNTRY, ADM1, GRID
Water-use efficiencyIND.WAT.stress.water_use_efficiencyWATWater stressadaptive capacity[USD]/m3COUNTRYSDG 6.4.1 WB_WDI ER.GDP.FWTL.M3.KD
Population using safely managed drinking waterIND.WAT.access.safely_managed_drinking_water.shareWATDrinking water and sanitationvulnerability%COUNTRY, ADM1, CITYSDG 6.1.1 WB_WDI SH.H2O.SMDW.ZS EPI UWD
Population using at least basic drinking waterIND.WAT.access.basic_drinking_water.shareWATDrinking water and sanitationvulnerability%COUNTRY, ADM1WB_WDI SH.H2O.BASW.ZS
Population using safely managed sanitationIND.WAT.access.safely_managed_sanitation.shareWATDrinking water and sanitationvulnerability%COUNTRY, ADM1, CITYWB_WDI SH.STA.SMSS.ZS SDG 6.2.1 EPI USD
Population with basic hand-washing facilitiesIND.WAT.access.basic_handwashing.shareWATDrinking water and sanitationvulnerability%COUNTRY, ADM1WB_WDI SH.STA.HYGN.ZS SDG 6.2.1
Water bodies with good ambient water qualityIND.WAT.quality.good_ambient_water_quality.shareWATWater qualityvulnerability%COUNTRY, ADM1SDG 6.3.2
Wastewater flows safely treatedIND.WAT.quality.wastewater_safely_treated.shareWATWater qualitycoping capacity%COUNTRY, CITYSDG 6.3.1 EPI WWT
Dependency ratio on external renewable waterIND.WAT.dependence.external_water_dependencyWATTransboundary dependenceexposure%COUNTRY
Transboundary basin area with operational cooperationIND.WAT.dependence.transboundary_cooperation.shareWATTransboundary dependencecoping capacity%COUNTRYSDG 6.5.2
07Quote

Water security risk index, world

The world reading of this index, every country as a tile and the largest movements since the previous edition.

NXS-GRX · WAT · 195 profiles · 0–10 scale
Water security risk index, world
—
Values publish with the edition; the interval, class and change appear here.
Previous edition
—
Range since 2016
—
Coupled composite
—
Coupling score S
—
Pulse, latest week
—
Outlook, 12 months
—
Method
Indicator Standard 1.0 · NXS-GRX 2026
Draws
1,000
Water security risk index, world, by edition

No released values yet. The first edition draws the history here with its interval band and class bounds.

The line is the point value by edition; the band is the 90% interval; dashed lines are the class bounds at 2, 3.5, 5 and 6.5.
No movements yet. Changes since the previous edition are listed here from the second edition on, with the indicators that drove them.
08Values

Country values

FIG 5 · Water security risk index: countries (values when released)
Loading the map
AndorraAntigua and BarbudaBahrainBarbadosComorosCabo VerdeDominicaMicronesia (Federated States of)GrenadaKiribatiSaint Kitts and NevisSaint LuciaLiechtensteinMonacoMaldivesMarshall IslandsMaltaMauritiusNauruPalauSingaporeSan MarinoSao Tome and PrincipeSeychellesTongaTuvaluHoly SeeSaint Vincent and the GrenadinesSamoa
Equal Earth · Natural Earth 1:110mValues when released
Until the first edition is released the map shows UN M49 regions or the Nexus Reports edition; it then shows this index's classes with each country's interval on hover. Countries are listed by name, never ordered by value.
Tiles
/api/v1/public/grix/risk-products/tiles/wat/{z}/{x}/{y}.mvt
Observation key
nis:IDX.WAT.stress.water_security_risk:{ISO3}:{YEAR}:A
10Validity

Crosswalks and validity checks

Crosswalks map leaf indicators to source code lists; established indices are used for validity checks, never re-weighted as inputs.

Code systemLeaf indicators mapped
SDG8
WB_WDI6
EPI3
11Across the Nexus

Platforms, standards and ways to take part

Field and service platforms of GCRI, GRF and GRA, the Nexus Risk Standards for this domain, learning, working groups and open calls. Every link is a live page.

12Cite

Cite and reuse

GCRI Canada (2026). The Global Risks Index (NXS-GRX): Water security risk index (GRX-IDX-WAT), Baseline Edition 2026. Preparatory working draft. https://risksindex.com/indices/water-security-risk/ UNI NXS-GRX-AR-000131.

See this index in every country profile

Each profile shows this index with its interval and class once released.