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What-If

Explore what could change.

Choose a place, a documented issue and one of its documented interventions, then set how far it goes.

ILLUSTRATIVE SCENARIO — NOT A SCIENTIFIC PREDICTION. Built from documented causes, impacts and solutions plus general qualitative patterns. It contains no modelled numbers.

3 · Intervention
PilotScaledTransformative

Adopted across much of the area, with dedicated budgets and enforcement.

Illustrative scenario

What if Mumbai took a scaled approach to “Storm drain upgrades and pumping stations”?

Starting point · documented

WaterSeverity: High
Monsoon flooding in Mumbai

Intense monsoon rainfall, high tides and constrained drainage cause recurrent flooding across the city.

The intervention · documented

Storm drain upgrades and pumping stations

Widening drains and building large pumping stations at outfalls to discharge water during high tide.

Reduces the duration and extent of waterlogging in served areas.

Schematic direction of change

Supply and demand measures can act within years, while groundwater, rivers and wetlands often take much longer to recover.

Schematic, unitless illustration: relative pressure over time without the intervention compared with the intervention in place. Not based on measured data.NowLonger term →Relative pressure (unitless)
Without the intervention With the interventionSchematic shape only — no data, units or dates.

Causes this could address

  • Extreme monsoon rainfallShort, intense bursts of rain can exceed the capacity of storm drains designed for lower intensities.
  • Tidal backwater effectsHigh tides reduce or block discharge from drains into the Arabian Sea.
  • Solid waste in drainsPlastic and other waste block drains and culverts, worsening local waterlogging.

Impacts that could ease

  • Disruption to transport and workSuburban rail and road networks can be halted, affecting millions of daily commuters.
  • Risk to life and propertyFlooding, building collapses and landslides during heavy rain cause deaths and damage, especially in informal settlements.

Wider reach at higher intensity is an assumption of this illustration.

How change might unfold

  1. Near term

    Operational gains such as reduced losses or new storage begin to show.

  2. Medium term

    Supply becomes more reliable in ordinary years if measures are sustained.

  3. Long term

    Aquifers and ecosystems recover slowly, if extraction and pollution stay below recharge and assimilation.

Faded stages are less likely to be reached at scaled intensity.

What this would not change

Rainfall variability and drought remain; interventions change how well the system copes, not the weather.

What it depends on

  • Sustained funding and institutional capacity
  • Consistent enforcement and monitoring
  • Local stakeholder support
  • Participation of affected communities

ILLUSTRATIVE SCENARIO — NOT A SCIENTIFIC PREDICTION. Built from documented causes, impacts and solutions plus general qualitative patterns. It contains no modelled numbers.

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