Plumbing Cistern First Flush Diverter Size Calculator
Actual first flush collection volume area×independent diversion depth×runoff fraction m³, no universal first flush depth or water pot ability guarantee. Actual independently matched units, regime, material/equipment and governing references; not a hydraulic code, safe pressure, water pot ability or operational approval.
Description
A first-flush volume follows from catchment area, diversion depth and runoff fraction.
A first-flush volume follows from catchment area, diversion depth and runoff fraction.1
The diversion depth must be independently established for the collection context. The calculation and input requirements are explained below.
When to use Plumbing Cistern First Flush Diverter Size Calculator
Enter nonnegative catchment area m² and independently chosen diversion depth meters, plus runoff fraction 0–1.
How to use Plumbing Cistern First Flush Diverter Size Calculator and how it works
- Prepare the measurements or independently established model inputs described below, with matching units and observation scope.
- Enter the required fields and run Plumbing Cistern First Flush Diverter Size Calculator.
- Read the result fields using the formula, output units, signs and ordering explained below.
- Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualContributingCisternCatchmentAreaSquareMeters | Actual Contributing Cistern Catchment Area Square Meters. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
| callerQualifiedFirstFlushDepthMeters | Caller Qualified First Flush Depth Meters. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
| callerMatchedRunoffFraction | Caller Matched Runoff Fraction. Use the units and matching context stated in the calculation below. | number | Required; fraction from 0 to 1; finite; other constraints below |
Enter nonnegative catchment area m² and independently chosen diversion depth meters, plus runoff fraction 0–1. Multiply to return first-flush volume m³. No diversion depth or potability conclusion is selected.
firstFlushM3=areaM2*diversionDepthM*runoffFraction Apply the input ordering, units and branch conditions stated above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the calculated or selected fields below. | object |
| result.value | Numeric result under the formula and output units explained above. | number |
{
"input": {
"actualContributingCisternCatchmentAreaSquareMeters": 10,
"callerQualifiedFirstFlushDepthMeters": 1,
"callerMatchedRunoffFraction": 0.5
},
"output": {
"result": {
"value": 5
}
}
}Limitations and assumptions
The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.
All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.
Alternative or Complementary methods
Use Plumbing Greywater Surge Tank Size Calculator for a complementary operation: A surge-storage ledger follows interval inflow minus outflow.
Use Plumbing Cistern Overflow Size Calculator for a complementary operation: Cistern overflow capacity depends on inlet runoff and overflow geometry.
References
Similar or alternative tools
- Plumbing Greywater Surge Tank Size Calculator
A surge-storage ledger follows interval inflow minus outflow.
- Plumbing Cistern Overflow Size Calculator
Cistern overflow capacity depends on inlet runoff and overflow geometry.