# Q3A · Discuss in detail the three key causes that resulted in Mumbai Floods 2005. Also sugg…

Subject: Disaster Management

Exam: TEE

Reader: https://deep-learning-study-room.vercel.app/dm/#tee/papers/paper-2023-07-05/q3a

Canonical: https://deep-learning-study-room.vercel.app/read/dm/tee/papers/paper-2023-07-05--q3a/

Actual older TEE paper · 100 marks · Q1 compulsory; any four of Q2–Q7

### Q3A. Discuss in detail the three key causes that resulted in Mumbai Floods 2005. Also suggest any 4 measures of mitigation for reoccurrence of such disaster. [10 marks]

#### Answer

1. **Event and setting:** Extreme rainfall on 26 July 2005 caused severe flooding in Mumbai and surrounding areas.
2. **Causes and vulnerability:** Intense rainfall interacted with inadequate or obstructed drainage, loss of natural storage, low-lying development and tide-related drainage constraints.
3. **Impacts:** Transport paralysis, deaths and injuries, housing damage, disrupted livelihoods and public-health risks.
4. **Response and recovery:** Rescue and shelter, restoration of services and attention to drainage, warning and urban-planning weaknesses.
5. **Lessons:** Maintain drains; protect wetlands and natural flow paths; plan outfalls and detention; issue local warnings; regulate exposed development.

#### Real case and learning connection · Mumbai floods, 2005

The Mumbai flood case links intense rainfall with urban drainage and development conditions. For an answer on mitigation, explain how maintaining drainage and protecting water-storage spaces address specific pathways of flooding; do not claim that any single measure prevents every extreme event.

[Case reference ↗](https://nidm.gov.in/PDF/Newsletter/6_nov_2005.pdf)

## Three interacting causes

1. **Exceptional rainfall.** A very large rainfall input rapidly produced runoff.
2. **Restricted conveyance.** Blocked or inadequate drainage and constrained river/outfall flow limited removal of water.
3. **Exposed urban development.** Impervious surfaces, loss of storage and low-lying development increased runoff and the people and assets affected.

## Four mitigation measures

1. **Maintain the catchment and natural storage.** Protect wetlands and floodplains and restore suitable vegetation. These measures slow runoff and store part of the floodwater, although they cannot eliminate extreme floods.
2. **Manage channels and drainage.** Remove blockages and maintain bridges, culverts and drains. Engineering surveys should guide selective desilting; indiscriminate excavation can damage banks and ecosystems.
3. **Use storage and coordinated reservoir operation.** Detention basins and reservoirs can hold water and release it more slowly. Forecasts, operating rules and downstream warnings are essential because storage and outlet capacity are finite.
4. **Apply floodplain zoning and resilient construction.** Keep new critical facilities outside high-risk zones. Where occupation is permitted, use suitable raised floors, protected utilities and evacuation access to reduce losses.