Most rainfed farming in India does not fail because of total rainfall. It fails because of distribution — a dry spell of two or three weeks at a critical crop stage, in a year where the seasonal total was perfectly adequate.
Water harvesting addresses exactly that. The aim is not to irrigate a crop fully from stored water. It is to have enough water available to give one or two life-saving irrigations when the rain stops at the wrong time.
What One Irrigation Is Worth
A single irrigation at flowering or grain filling can be the difference between a normal harvest and a failed one. On a rainfed crop, that irrigation is often worth more than everything else spent on the field that season.
This is why farm ponds pay back on farms where full irrigation would never be economic.
Siting a Farm Pond
Placement decides whether the pond fills.
- Lowest practical point of the catchment, so runoff arrives by gravity
- Away from large trees whose roots damage lining and whose leaves fill the pond
- On less productive ground where possible — a pond removes that area from cultivation permanently
- Where the inlet can be controlled, so you can shut off flow once full
- Not immediately adjacent to a structure whose foundation could be affected by seepage
Sizing
Pond size should be calculated from your catchment area, local rainfall pattern and soil infiltration, not chosen by eye. Your district watershed office or KVK can work this out. A pond too small for its catchment overflows and erodes; one too large for its catchment never fills and wastes the excavation cost.
Depth matters as much as area. A deep pond of a given volume loses much less to evaporation than a shallow one of the same volume, because evaporation is driven by surface area. In hot dry regions this difference is substantial over a season.
To Line or Not to Line
In sandy or highly permeable soil, an unlined pond drains within weeks and is effectively useless for storage. Lining is then unavoidable.
- Unlined — works only in heavy clay soils with low infiltration. No cost beyond excavation.
- Plastic sheet lining — the common option. Requires a smooth base free of stones and roots, adequate sheet thickness for durability, and proper anchoring in a trench around the rim. Cheap sheet fails within two or three seasons.
- Cement lining — long lasting and much more expensive. Justified where the pond serves a permanent purpose.
Note that lining a pond stops it recharging groundwater. If your objective is to raise the water table for a borewell rather than to store surface water, you want the opposite — an unlined structure or a dedicated recharge pit.
Recharge Structures
Where the aim is groundwater rather than surface storage:
Recharge pit near a borewell
A pit filled with graded material — boulders at the base, then gravel, then coarse sand — directs filtered runoff toward the aquifer instead of letting it run off the land. Farmers in hard rock areas commonly report improved borewell yield and longer pumping duration after monsoon.
Contour bunds and trenches
On sloping land, bunds along the contour slow runoff and give water time to infiltrate. They also reduce soil erosion, which on a slope is often the more valuable effect.
Check dams and gully plugs
Small structures across natural drainage lines slow flow and hold water long enough to soak in. These are usually built as community works under watershed programmes rather than by individual farmers.
Safety
This matters more than anything else in this article. Farm ponds are a serious drowning hazard, particularly for children and livestock.
- Fence the pond. Not optional, especially near a house or a path used by children.
- Provide at least one gently sloping side or steps so anything that falls in has a way out
- Keep a rope or bamboo pole at the edge
- Tell children clearly and repeatedly that the pond is not for play
- Ensure livestock cannot access steep-sided lined ponds — plastic lining is slippery and an animal cannot climb out
Maintenance
Desilt before each monsoon; silt reduces capacity every year. Clear the inlet channel so runoff can actually enter. Inspect lining for tears and repair them before the pond fills. Check that the overflow outlet is clear, because an overtopping pond can breach and cause more damage than it prevents.
Support Available
Farm ponds and recharge structures are supported under central and state watershed and micro-irrigation programmes, and under MGNREGA in many states. Rates, eligibility and application routes differ by state and change with programme cycles. Ask at your district watershed development office or block office what is currently available in your area, and get approval before starting work.
Pond design must suit your soil, slope and rainfall. Consult your district watershed office or agriculture department before excavation. Always fence any water storage structure on farmland.