Clearing Three Lanka Villages as the Godavari Rises
At 6 a.m. the Dowleswaram barrage gauge on the Godavari reads 14.0 feet and is rising 0.3 feet an hour. The third warning level is 14.0 feet, and the control room expects the rise to continue for at least ten hours. A sub-inspector has to clear three lanka villages in the delta. Village X has 620 people, 260 of them children or elderly, and is reached by a single causeway whose deck is 2.4 feet above the present water level, 6 km from the road head. Village Y has 900 people and a motorable road that stays 4 feet above the present level, 9 km out. Village Z has 350 people on an islet reachable only by two country boats that together carry 25 people an hour, and its ring bund is already seeping. The mandal has four buses of 50 seats, one launch and 11 police personnel, including the sub-inspector.
1. Calculate when the causeway to Village X will be under water, work out the comparable margin for Village Y, and state the order in which the three villages must be evacuated.
Read the worked answer
Village X causeway Freeboard 2.4 ft, rise 0.3 ft per hour → 2.4 ÷ 0.3 = 8 hours. From 6 a.m. the deck is submerged at about 2 p.m. Even before that, the causeway becomes unusable for buses when water is lapping the deck, so the practical deadline is earlier - around noon.
Village Y road 4 ÷ 0.3 = 13.3 hours → about 7:20 p.m. Y has roughly twice X's margin, though its population is larger.
Village Z No road at all; the constraint is boats, not water level. The seeping ring bund means Z can flood before the river overtops anything, and loss of the bund would strand 350 people.
Order of work
- Z and X simultaneously, starting now. Boats must be launched immediately because the boat rate is the slowest of all three (25 people an hour). Buses go to X at once so that the causeway is cleared well before noon.
- Y last, but its loading point and route must be reconnoitred by mid-morning so that buses returning from X can be turned around without a gap.
A plan that evacuates alphabetically, or that leaves Z for the afternoon because "the road is still open", is the failing answer.
2. How long will it take to move Village Z's entire population by the available boats, and what should the sub-inspector do when he sees the figure?
Read the worked answer
Boat capacity 350 people ÷ 25 people per hour = 14 hours, i.e. from 6 a.m. to about 8 p.m., if the boats run without a break and the river allows night operation. They will not: there is loading time, the trip length, fuel and crew rest, and the current will slow the return leg.
What that means In the eight hours before X's causeway drowns, the boats can move only about 200 people, leaving 150 on the islet when the bund is already seeping. The plan therefore fails on capacity and must be reinforced rather than merely scheduled.
Actions
- Requisition additional country boats and the mandal launch through the control room immediately; fisheries department and neighbouring mandal boats are the nearest source.
- Evacuate in priority order - children, the elderly, pregnant women and the sick first, then the rest - and record names so that a missing person can be identified later.
- Pre-position a high-point assembly ground on the islet with a raised platform, drinking water and lights, so that people are not standing on a seeping bund while waiting for a boat.
- If the bund breaches before the boats finish, shift from ferry evacuation to rescue of people already marooned, using the launch and life jackets, and inform the control room that Z has become a rescue and not an evacuation task.
3. Village Y has 900 people, 300 cattle, 400 acres of paddy and twelve aquaculture ponds. Explain, using the geography of lanka villages and the local economy, why the people will resist leaving and how the sub-inspector should handle it.
Read the worked answer
Why lanka villages flood Lanka lands are deltaic silt formations between distributaries of the Godavari. They are low, flat and often below the river's high flood level, and are protected by earthen ring bunds rather than by high ground. When the river is in spate, three things happen at once: the main channel rises, water seeps through and eventually overtops the bund, and backwater and a raised water table flood the fields from below. Rain has nowhere to drain because the outfall is the same swollen river. So the village can flood even without a visible breach.
Why people resist Their entire asset base is immovable and is standing in the field: paddy that is weeks from harvest, twelve aqua ponds whose shrimp or fish will die within hours if the pumps stop, and cattle that cannot be put on a bus. A family that leaves loses everything it has borrowed against.
How the sub-inspector should handle it
- Do not argue about the water level; argue about timing. Once the road goes under, no bus can come back.
- Arrange a separate cattle plan - a holding ground on higher ground, a route, and a time - because families will not leave without the cattle, and 300 animals cannot be carried on four buses.
- Get the panchayat to list households, livestock and pond owners in advance so that the last bus is not delayed by an argument.
- Warn the aqua-pond owners to switch off pumps and open the pond bunds to equalise pressure before the flood peak, which saves the ponds even if the crop is lost.
- Record the evacuation, leave a police picket on the road head for the property, and tell the people when they will be brought back.