Water Resources of Maharashtra: Availability, Distribution and Variability
This domain tests how Maharashtra's water is distributed in space and time, and why availability is not the same as rainfall. Expect questions on monsoon concentration, regional disparity, surface storage and groundwater.
Core rules
- Maharashtra receives most rain in June–September; the long-period state average is roughly 1,000–1,200 mm, but Konkan and the Western Ghats can exceed 2,500 mm while rain-shadow districts of Marathwada and Vidarbha often get 500–700 mm.
- East-flowing Godavari and Krishna basins drain most of the plateau; west-flowing Konkan rivers are short and steep. Large dams store water, but command areas and cities may lie far from the storage.
- Availability depends on harvestable yield, storage, evaporation and conveyance-not just rainfall depth.
Worked example
Two districts both record 700 mm. District A has shallow soils and 30% runoff in four months; District B has deep soils and 15% runoff. On 1,000 ha, A produces 0.30 × 0.7 m × 10,000,000 m2 = 2.1 million m3 of runoff; B produces 1.05 million m3. If A can store only 20% and B 50%, usable volumes are 0.42 and 0.525 million m3. The wetter-looking district is not automatically better supplied.
Traps
- Equating rainfall with water availability.
- Assuming dam storage is local supply.
- Ignoring seasonality and evaporation.
- Comparing districts without accounting for inter-basin transfers.