Check Dam Storage & Hold Water, Recharge Wells
Stores impounded water
Enter the length, width and depth of the impounded pool to get the gross and usable volumeafter a silt allowance, in cubic metres and litres — for recharge and lifesaving irrigation planning.
Size your check dam pool
Next: plan to recharge or draw up to 1,800 m³ (~1,800,000 L) per fill, and desilt the pool periodically to protect that volume.
Real ponds taper, so gross volume is approximate; usable storage also depends on seepage and evaporation between fills.
Check dam storage — key facts
- Gross volume
- = length × width × depth
- Usable volume
- = gross − silt allowance
- 1 m³
- = 1,000 litres
- Purpose
- Recharge + lifesaving irrigation
- Silt
- Fills the basin over years
- Plan on
- Usable, not gross volume
- Maintenance
- Desilt every few years
- Privacy
- Runs in your browser; nothing uploaded
A small wall across a gully banks water for the dry season
A check dam is one of the cheapest, most powerful watershed tools there is: a modest barrier across a stream or gully that catches runoff and holds it as a pool. That impounded water soaks down to recharge wells and borewells, and stands ready to give crops a single lifesaving irrigation when a dry spell threatens at flowering or grain fill. The catch is that silt arrives with every monsoon and slowly eats into the basin, so the storage you can rely on shrinks over time.
This tool computes the gross pool volume from length, width and depth, then deducts a silt allowance to give the usable volume in m³ and litres — the figure to plan your recharge and command area on. Pair it with the Farm Pond, Recharge Pit, Tank Command Area and Rainwater Harvesting tools to design a full water-harvesting system.
Bank the runoff
Hold flowing water instead of losing it.
Recharge wells
Impounded water soaks down to the aquifer.
Plan on usable
Silt allowance gives the realistic volume.
Lifesaving water
A pool for one critical irrigation.
Frequently Asked Questions
What is a check dam?+
A check dam is a small barrier built across a stream, nala or gully to slow and impound flowing water. It holds water that would otherwise rush away, letting it soak into the ground to recharge wells and aquifers and providing a pool for lifesaving irrigation during dry spells. Gully plugs and nala bunds work on the same principle.
How is the stored volume calculated?+
The gross stored volume is length × width × depth of the water body held behind the dam. For a pool 30 m long, 10 m wide and 1.5 m deep that's 30 × 10 × 1.5 = 450 m³. This tool computes that volume and converts it to litres so you can plan recharge and irrigation.
What is the silt allowance?+
Every monsoon a check dam traps sediment, and over the years that silt fills part of the basin and reduces the water it can hold. The silt allowance is a percentage you subtract from the gross volume to estimate the realistic usable storage over the structure's working life, rather than its brand-new capacity.
What is the usable volume?+
Usable volume is the gross volume minus the silt allowance — the water you can actually count on for recharge and irrigation once sedimentation is accounted for. Planning your command area on the usable volume, not the gross, avoids over-promising water that silt will eventually displace.
How does a check dam help recharge?+
By holding water in contact with the streambed for longer, a check dam gives it time to percolate down to the water table instead of running off. This raises nearby well levels, extends the life of borewells, and is one of the most cost-effective watershed measures for reviving groundwater.
What is lifesaving irrigation?+
It's a single, critical irrigation given at the most sensitive crop stage — like flowering or grain filling — when a dry spell would otherwise cause heavy yield loss. A check dam's stored pool can supply just enough water for this one protective irrigation across the nearby fields.
How do I turn the volume into command area?+
Divide the usable volume by the depth of water a crop needs per irrigation (in metres) to get the area one filling can serve. For example 400 m³ of usable water at a 50 mm (0.05 m) lifesaving depth can cover 400 ÷ 0.05 = 8,000 m² ≈ 0.8 hectare.
How big should a check dam pool be?+
It depends on the gully cross-section, the safe height that won't overtop or wash out, and the catchment that feeds it. Size the dam so the impounded depth stays within stable banks, then use this tool to see the resulting volume and check it against your recharge and irrigation goals.
How often should silt be removed?+
Desilting every few years restores lost capacity and keeps the dam working as designed. Watch the trapped sediment level after each monsoon; when it noticeably reduces the pool, schedule desilting. Reusing the rich silt on fields is a bonus that also pays back the effort.