A Walled-City Ward After an Extreme Rainstorm
On 25 July, a walled-city ward in Jodhpur (population 1.1 lakh, area 4.2 km²) received 187 mm of rain in 9 hours. The storm water drains were built in 1978 for a 12 mm/hour design intensity. Two natural nallahs crossing the ward have been built over since 1995. Water stood 1.2 m deep in the low-lying Sarafa Bazaar for 14 hours; 38 shops were inundated and a 60-year-old wall collapsed, killing 2 people. The municipal corporation has ₹8 crore for immediate works and must choose among: desilting and restoring the two nallahs (₹3 crore but requires demolishing 40 encroachments), a 2.5 km storm-water drain to the Kaylana lake outlet (₹7 crore), or a pumping station (₹2 crore, recurring ₹40 lakh/year). The ward has a heritage listing, and the state disaster management plan classifies it as 'high risk'. The corporation must also decide whether to issue relocation notices to 40 households.
1. Which intervention should the corporation prioritise, and how should the design storm and return period inform that choice?
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Priority: restore the two nallahs, with temporary pumping as a bridge, and treat the new drain as a longer-term option.
The storm delivered 187 mm in 9 hours, an average of about 21 mm/hour, well above the 12 mm/hour design intensity of the 1978 drains. The event is therefore larger than the system's design storm; the drains did not simply fail through poor maintenance, they were overwhelmed. But the built-over nallahs made the flooding much worse by removing the ward's natural conveyance. Restoring them re-establishes the cheapest and largest additional capacity.
The 40 encroachments are the difficult part. Demolition must be preceded by survey, notice, hearing and compensation or resettlement, or it will be stayed and the monsoon will arrive first. The ₹3 crore estimate is realistic only if that process is funded.
A new 2.5 km drain at ₹7 crore consumes nearly the entire budget and still needs a verified outfall and gradient; if the Kaylana outlet cannot accept the flow, it transfers flooding downstream. A pumping station at ₹2 crore can remove ponded water quickly but has high recurring cost and does nothing for the next storm's inflow. The defensible package is nallah restoration plus one or two pumps for the lowest pocket, with the new drain designed and funded in the next cycle using a higher design storm and a hydraulic model.
2. Critique the proposal to issue relocation notices to the 40 households from a disaster risk reduction and social vulnerability perspective.
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Relocation may be necessary for a few households, but blanket notices are poor disaster risk reduction.
The households are not necessarily the cause of the hazard. The ward's risk comes from built-over nallahs, undersized drains and extreme rainfall; moving 40 families does not fix any of these. Relocation also tends to displace the poorest and least mobile residents, who depend on the bazaar for work and have no alternative housing. It can destroy livelihoods and social networks, which are themselves protective factors in a disaster.
A defensible sequence is: first, reduce the hazard through nallah restoration, drainage and early warning; second, assess each structure for structural safety, not just location; third, offer voluntary, participatory relocation with compensation, secure tenure and livelihood support only where a building is genuinely unsafe or where the drainage corridor cannot be cleared otherwise. Heritage-listed buildings need conservation advice, not demolition by notice.
The ward should also have a local emergency plan: a public address system, marked evacuation routes from Sarafa Bazaar, a trained ward disaster committee, and a rule that shops close when rainfall exceeds a stated threshold. These measures save lives during the next event while the engineering works are being built. Issuing notices without them would create legal conflict and would not reduce risk.