Three Floods, Three Teams: The State Emergency Operations Call
It is 26 August. As the duty officer in the Haryana state emergency operations centre you receive three simultaneous reports.
(i) The Ghaggar at Ratia in Fatehabad district is flowing 30 cm above the warning level, spreading over fields and cutting approach roads to about a dozen hamlets.
(ii) Heavy rain in the catchment in Rajasthan has sent the Sahibi stream through Rewari and Jhajjar, and low-lying colonies in Gurugram are waterlogged up to waist depth; the Najafgarh drain is running full, so water is not receding.
(iii) The Hathnikund barrage has released about 2.5 lakh cusecs into the Yamuna, with the peak expected downstream in 10 to 12 hours and embankment patrols reporting seepage at two points.
You have three SDRF teams, one boat unit and one drone. The teams cannot be split. The Additional Chief Secretary asks for a deployment order with reasons, not a list of districts.
1. Deploy the three SDRF teams, the boat unit and the drone, and justify each choice. State two developments that would make you re-deploy.
Read the worked answer
Yamuna, Yamunanagar-Karnal belt: first SDRF team plus the boat unit, pre-positioned now. A barrage release gives a measured volume and a known lead time. The danger is volume and embankment failure, and the assets must be in place before the peak, not travelling towards it. Boats are most useful here because the water will be deep and fast.
Gurugram: second SDRF team plus the drone, and a written request for pumps. Urban waterlogging in colonies at waist depth traps people in basements and ground floors over a small area. Boats are of limited use in shallow, debris-filled streets; the drone's job is to locate trapped people and confirm which underpasses and basements are submerged. The real fix is pumping and drain clearance, which the municipal body must be tasked to do in writing.
Ghaggar at Ratia: third SDRF team, held mobile. A 30 cm breach of the warning level on a broad, shallow, slow-spreading stream is an evacuation-and-relief problem for scattered hamlets, not a rescue problem yet; a mobile team covering the hamlets is a better use than a static one.
Re-deploy if: (a) embankment patrols report a breach or a boil on the Yamuna, or (b) a hamlet on the Ghaggar reports people on rooftops or a road-cum-canal bund gives way. Either moves the boat unit immediately.
2. Explain the hydrological difference between the three systems and why their warning lead times differ. List the districts downstream of the Ghaggar in Haryana in the order an evacuation advisory should travel.
Read the worked answer
Yamuna is a perennial, snow- and rain-fed river regulated at the Hathnikund barrage in Yamunanagar district. Because release volumes are measured, the flood wave is predictable and the lead time is comparatively long; the operational task is to pre-position and patrol embankments.
Ghaggar is a seasonal, monsoon-fed stream that rises in the Shivaliks, is flashy in its upper course near Panchkula and Ambala, then flattens out and spreads widely across the plains before entering Rajasthan near Hanumangarh, where it finally dissipates in the desert. It has no mouth and no dependable dry-season flow, so it is monitored as a spreading-sheet flood rather than a river with a defined channel - and its peak can arrive with very little notice.
Sahibi is a short, rain-fed stream that rises in the Rajasthan hills and runs through Rewari and Jhajjar into the Najafgarh drain in Delhi. It carries water only after heavy rain, so its 'flood' is often drainage backflow in Gurugram rather than river overflow; levels can fall within hours.
Ghaggar sequence for advisories: Panchkula and Ambala first, then Kaithal, then Fatehabad, then Sirsa, before the stream crosses into Rajasthan. Advisories must travel in that order because the wave reaches each district in turn.
3. What three pieces of data would you demand before issuing a public advisory, and what caveat must district magistrates be told about the Sahibi?
Read the worked answer
Three data demands: (1) the upstream trend, not just the current level - the last three readings on the Ghaggar gauge and the barrage release schedule for the next 12 hours, since a single reading cannot show whether a peak has passed; (2) the rainfall forecast for the next 24 hours in the relevant catchment, because a receding stream with 100 mm of forecast rain is a different risk from a receding stream with none; (3) ground-truth reports from patwari, canal and embankment staff on seepage, road submergence and people already cut off, because gauge data does not tell you who is trapped.
The caveat on Sahibi: magistrates must be told that it is a rain-fed, ephemeral stream, not a perennial river, and that flooding in Gurugram is frequently the Najafgarh drain running full rather than the stream overtopping. Two consequences follow: the warning must be tied to rainfall in the Rajasthan catchment and to drain capacity, not to a river gauge alone; and the water can recede within hours, so residents moved out may need to be held back from returning into basements and underpasses until the drain level is confirmed to be falling. A warning that assumes a slow, predictable river will be wrong in both directions.