Well Yield Calculator
Estimate well yield from pumping-test data and step-drawdown behaviour.
Well Yield Estimate
| Parameter | Result |
|---|---|
| Observed Drawdown | — |
| Specific Capacity | — |
| Allowable Drawdown | — |
| Estimated Yield | — |
Step-Drawdown Test Data
| Step |
Pumping Rate
|
Pumping Water Level
|
|---|
Step-Drawdown Analysis
| Parameter | Result |
|---|---|
| Allowable Drawdown | — |
| Coefficient B | — |
| Coefficient C | — |
| R² | — |
| Estimated Yield | — |
These are yield estimates based on the entered pumping-test data. They should not be interpreted as guaranteed long-term sustainable yield. Actual well performance can depend on aquifer conditions, well construction, duration of pumping, recharge and seasonal groundwater conditions.
What Is Well Yield?
Well yield is the rate at which water can be pumped from a well under specified test conditions. It is commonly expressed in litres per minute, litres per second or cubic metres per hour.
A pumping test measures how the water level changes as water is withdrawn from the well. The difference between the static water level and the pumping water level is called drawdown. The relationship between pumping rate and drawdown provides the basis for estimating well yield.
Drawdown is the difference between the static water level and the pumping water level.
How Well Yield Is Calculated
The Basic Estimate uses the observed pumping rate and drawdown to calculate the well's specific capacity. Specific capacity indicates how much water is produced for each unit of drawdown during the test.
The calculator then applies the observed specific capacity to the selected allowable drawdown to estimate the corresponding well yield.
Advanced Step-Drawdown Analysis
The Advanced method uses measurements from multiple pumping steps. These observations describe how drawdown changes as the pumping rate increases.
Here, s is drawdown, Q is pumping rate, and B and C are fitted well-loss coefficients. The fitted relationship is used to estimate the pumping rate corresponding to the selected allowable drawdown.