Warabandi & Know Your Canal Turn to the Minute
Computes each farmer's turn
Warabandi shares one canal outlet's water by time, in proportion to land — enter the discharge, the rotation cycle and every holding's area to get each farmer's turn duration, start/end clock time and the depth delivered, with the filling-loss deduction built in.
Enter the outlet & holdings
Tap a colour dot to highlight your holding on the clock.
Next: open the channel for your turn from Day 2 18:00 to Day 5 19:22 — that's 73h 13m of flow at 30 L/s, delivering about 226 mm over your 3.5 hectare. Allow the first 10.2 min for the khal to fill before water reaches your nakka, and close on time so the next holding gets its full turn.
Warabandi turn time is pro-rata to holding area: turn = (holding area ÷ command area) × (cycle − total filling loss). Depth = discharge × turn time ÷ area. Filling (khal-bharai) minutes are deducted at each turn change. Sources: CWC / state irrigation warabandi rules; Malhotra (1982, CBIP). Confirm against your outlet's official warabandi (osrabandi) register.
Warabandi schedule — key facts
- Turn time
- (area ÷ command) × productive cycle
- Productive cycle
- cycle − total filling loss
- Depth per turn
- discharge × turn time ÷ area
- Standard cycle
- weekly (168 hours)
- Filling loss
- 5–15 min per turn change
- Volume
- discharge (L/s) × turn seconds ÷ 1000
- 1 acre
- 4046.86 m²
- 1 hectare
- 10000 m²
- Fairness rule
- equal depth per area, head to tail
- Privacy
- Runs in your browser; nothing uploaded
Warabandi cycle and filling-loss presets
Two settings shape the roster: the rotation cycle (how often the turns repeat) and the filling-loss allowance deducted at each turn change. Weekly cycles keep every farmer's slot on the same days; longer cycles stretch the gap between turns. Lined channels fill quickly and carry a smaller deduction.
| Rotation cycle | Hours | Days | Use |
|---|---|---|---|
| Weekly (7 days) | 168 | 7 | Classic warabandi roster |
| 10-day | 240 | 10 | Larger command areas |
| Fortnightly (14 days) | 336 | 14 | Scarce-water / large command |
| 5-day | 120 | 5 | Tight, frequent rotation |
| Filling loss / turn | Minutes | Channel |
|---|---|---|
| None (lined channel) | 0 | Fully lined, no fill time |
| Low (5 min) | 5 | Short / lined khal |
| Standard (10 min) | 10 | Typical earthen watercourse |
| High (15 min, long khal) | 15 | Long unlined khal |
Sources: Central Water Commission (CWC) and state irrigation-department warabandi/osrabandi rules; Malhotra, S.P. (1982), "The warabandi system and its infrastructure", CBIP. Confirm against your outlet's official warabandi register.
How warabandi shares water fairly
A canal outlet delivers a roughly constant discharge, so the only thing left to share is time. Warabandi divides the rotation cycle into turns sized strictly by land area: if your field is one-fifth of the land served by the outlet, you get one-fifth of the flow time each cycle. Because discharge is constant, equal time-per-area means equal water-depth-per-area — the head-reach farmer and the tail-ender both receive the same millimetres over their fields, which is the equity claim at the heart of the system.
The only adjustment is the filling loss: when each turn begins, water must first travel down and fill the empty watercourse before reaching the field, and that time produces no irrigation. Warabandi deducts a fixed filling allowance per turn change so this unproductive time is borne fairly across all holdings. This calculator takes your outlet discharge, the cycle length and every holding's area, deducts the filling loss, and lays out each farmer's turn duration, the exact clock window, and the depth of water that turn delivers.
How to use it
- 1Choose the rotation cycle (weekly is the classic warabandi) and your area unit (hectare or acre).
- 2Enter the outlet discharge in litres per second and pick the per-turn filling-loss allowance.
- 3Add every holding on the outlet with its name and area — use Add to include more.
- 4Tap your holding's colour dot to highlight it on the rotation clock.
- 5Read your turn duration, the start and end clock time, and the water depth delivered — and check it against your crop's requirement.
Frequently Asked Questions
What is warabandi and how is the turn time calculated?+
Warabandi (literally 'turn-fixing') is a rotational canal-water system where each farmer on an outlet gets a fixed turn (wari) in the rotation cycle (bandi), in proportion to their land. The turn time = (holding area ÷ total command area) × (cycle length − total filling loss). A 2-hectare holding on a 10-hectare outlet running a 7-day (168 h) cycle gets one-fifth of the cycle — about 33–34 hours each week.
How do I work out my own warabandi turn?+
Take your area as a share of all the land on the outlet, then multiply that share by the productive cycle hours (the cycle minus the filling-loss deductions). This calculator does it for every holding at once and shows your turn highlighted on the rotation clock, with the start and end clock time and the water depth you receive.
Why is warabandi based on time, not volume?+
Because the canal outlet delivers a roughly constant discharge, sharing time is the same as sharing water: a holding that runs the channel twice as long gets twice the volume. Allocating by time in proportion to area means every field — head reach or tail-ender — receives the same depth of water per unit area, which is the fairness principle behind warabandi.
What is the filling loss (khal-bharai) and why is it deducted?+
When a farmer's turn starts, water first has to fill the empty watercourse (khal) before it reaches their field — that filling time is unproductive. Warabandi rules deduct a fixed allowance (often 5–15 minutes per turn change) so the productive flow time is shared fairly. Lined channels fill faster, so they carry a smaller filling-loss deduction; long earthen khals carry more.
How much water depth does each turn deliver?+
Depth (mm) = outlet discharge × turn time ÷ holding area. For example, 30 L/s flowing for 84 hours onto 2 hectares delivers 9072 m³, which spread over 20,000 m² is about 454 mm. The calculator reports this depth per holding so you can check it against the crop's irrigation requirement for the cycle.
Is warabandi the same as osrabandi?+
They are closely related rotational systems. Warabandi fixes each cultivator's turn in a published weekly roster; osrabandi (or 'osra') is a similar turn-based rotation used in some regions, sometimes rotating the roster's starting point each week so no one is permanently stuck with an inconvenient (e.g. night) slot. The turn-time arithmetic — pro-rata to area — is the same.
How long is a typical warabandi cycle?+
The classic warabandi cycle is weekly (7 days = 168 hours), so the roster repeats every week and each farmer's slot stays on the same days. Some systems use 10-day or fortnightly cycles where water is scarcer or the command area is large. This tool supports 5-day, weekly, 10-day and fortnightly cycles.
What happens to the tail-ender's turn?+
Under a strict warabandi the tail-ender gets exactly their area's share of time, the same as everyone else — that is the system's main equity claim. In practice tail-enders lose more to conveyance and seepage along a longer channel, which is why the filling-loss allowance and channel lining matter most for them. The calculator gives the on-paper fair turn; field losses are separate.
Can the warabandi roster start at a different point each week?+
Yes — many systems rotate the starting holding each cycle so that the same farmer is not always allotted the least convenient hours (such as the middle of the night). The turn durations stay the same; only the order shifts. This calculator lays out the durations and clock windows for one cycle starting from the first holding listed.
Does a larger holding get a longer turn?+
Yes — directly proportional. If your land is 30% of the command area, you get 30% of the productive cycle time. Doubling your area doubles your turn (and the water volume), but the depth per unit area stays the same as everyone else's, because both your time and your area scale together.
Is warabandi a fair way to share canal water?+
It is designed to be: by tying each turn strictly to land area and publishing a fixed roster, warabandi removes day-to-day negotiation and gives every cultivator a predictable, equal depth of water per acre. Its weaknesses are conveyance losses (worse for tail-enders) and rigidity in droughts, which is why supplementary rules and lining are used alongside it.