Sugarcane, a shrinking aquifer and three competing proposals
A semi-arid district in the Deccan receives 615 mm of rain against a normal of 745 mm, the third consecutive deficit year. Of its 14 blocks, 9 are officially over-exploited for groundwater, and depth to water in observation wells has fallen from 38 m in 2012 to 71 m in 2022. Sugarcane covers 9 per cent of the cropped area but takes about 55 per cent of irrigation water. The state supplies canal water free and bills agricultural pumps at a flat monthly rate. Cotton and pigeon pea, grown on the rest of the area, are almost entirely rain-fed. Fluoride above 1.5 mg/l has been reported in 11 habitations. The irrigation department proposes extending the canal by 22 km to command 4,000 new hectares. A farmer group instead demands a higher support price for sugarcane and an assured crushing date. A third proposal, from the watershed cell, asks for check dams and farm ponds on the upper slopes.
1. Rank the three proposals for the coming budget year and defend the first choice using the numbers given.
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Rank: check dams and farm ponds first; the sugar price and crushing date second, but only with water conditions attached; canal extension last.
- The ratio that decides it: sugarcane is 9 per cent of cropped area and takes 55 per cent of irrigation water, so its water intensity is roughly six times that of the rest. Any proposal that adds water to the command without touching that ratio simply enlarges the deficit.
- Recharge on the upper slopes acts on the cause, not the symptom. Rain that now runs off in a few hours is held where the rain-fed cotton and pigeon pea are grown - the crops of farmers who receive no canal water at all. It is scale-neutral (a farm pond on half a hectare is possible), quick to build, and it works on the 71 m well depth and the 9 over-exploited blocks at the same time.
- The canal extension commands 4,000 new hectares with water already committed. In practice it will be met by cutting tail-end deliveries to existing users, converting an existing shortage into a new dispute.
- The price and crushing date matter to farmers, but they raise the return on the most water-intensive crop. They become defensible only with drip, volumetric canal charges and a crushing-date penalty.
Ranking by cost per unit of water saved and by who gains: recharge and farm ponds, then a conditioned sugar package, then the canal.
2. Explain why a farmer's decision to grow sugarcane is rational, and why an appeal to save water will not change it.
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It is rational because the farmer bears almost none of the cost.
- Sugarcane has a named buyer, a state-advised price and a three-to-five-year ratoon, so its price risk is low and the planting cost is sunk. Pigeon pea has no assured procurement and its price can halve in a good year. Choosing the crop with the stable buyer is what an economist would predict.
- Canal water is free and the pump is billed at a flat monthly rate, so the marginal cost of the next cubic metre is close to zero. The falling water table is a cost borne by everyone and by the future, not by the person choosing what to sow. A moral appeal asks him to bear a cost his neighbour will not, which predicts the observed outcome: no change.
- Change the cost structure and the choice changes: volumetric canal pricing, metered or smart-card pump tariffs, drip subsidies that cut sugarcane's water use by roughly 40 to 50 per cent so the crop can stay, and a procurement price for pulses and oilseeds that matches sugarcane returns.
Telling farmers to abandon the crop also ignores the three-year payback on planting and the absence of any alternative assured buyer in the block.
3. Which two data items would you require before approving the 22 km canal extension, and why those two?
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The two items that must precede approval:
- A water balance for the existing and proposed command at 75 per cent dependability, showing volumes actually delivered at the tail-end over the last five years, not volumes released at the head. Without it the extension has no identified supply, and the 4,000 hectares remains an input figure rather than an outcome.
- A baseline of groundwater levels and a fluoride map for the new command area. A canal can raise the water table and dilute fluoride in some patches, or trigger waterlogging and salinisation in others; with 11 affected habitations, the chemistry is part of the decision, not an afterthought.
Two further items would be needed before construction: the landholding distribution in the new command, to see whether smallholders gain or the benefit is captured by cultivators already at the canal head; and an enforceable withdrawal cap, since free canal water plus flat-rate electricity is precisely why the district is in this position.
Rule of thumb for the answer: no new command until the old command's tail-end deliveries are on the record.