Verify the inputs
Measure or document each input. If a value is only an estimate, record its source and test a conservative alternative.
Wells & water/ CALCULATOR
Rainwater storage balance for a dry period
Compare usable tank water with expected demand and dependable inflow over a chosen period.
FROM ESTIMATE TO ACTION
Use the result, not just the number.
Keep the calculation traceable
Save the input link or copied result together with the date, units and assumptions. A number without its inputs cannot be checked later.
Confirm the decision
Compare the estimate with the related guide, current product data and requirements that apply at your location before buying or building.
Inputs to verify
- Water currently stored (L)
- Use the measured or estimated volume at the start of the scenario.
- Protected reserve (%)
- Volume kept unavailable for uncertainty, sediment clearance or emergency use.
- Planned daily demand (L/day)
- Include only uses supplied from this tank during the scenario.
- Dependable daily inflow (L/day)
- Use zero for a completely dry scenario; avoid optimistic rainfall assumptions.
- Scenario duration (days)
- Choose a consecutive period relevant to local dry spells or supply interruptions.