1. What is Well Efficiency?

Well Efficiency refers to the ratio of the drawdown in the aquifer at the radius of the pumping well to the drawdown inside the well. It is a measure of how effectively a well can extract water from an aquifer.

2. How Does the Calculator Work?

The calculator uses the Well Efficiency equation:

Where:

• \( E \) — Well Efficiency
• \( s \) — Change in Drawdown (Meter)
• \( s_t \) — Drawdown Inside the Well (Meter)

Explanation: The equation calculates the efficiency of a well by comparing the drawdown in the aquifer to the drawdown inside the well itself.

3. Importance of Well Efficiency Calculation

Details: Calculating well efficiency is crucial for assessing the performance of water wells, determining optimal pumping rates, and identifying potential issues with well construction or aquifer characteristics.

4. Using the Calculator

Tips: Enter the change in drawdown and drawdown inside the well in meters. Both values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is a good well efficiency value?
A: Well efficiency values typically range from 0 to 1, with values closer to 1 indicating higher efficiency. The ideal value depends on specific well conditions and aquifer characteristics.

Q2: What factors affect well efficiency?
A: Well efficiency can be affected by well construction, screen design, aquifer properties, pumping rate, and well development techniques.

Q3: How is drawdown measured?
A: Drawdown is typically measured using pressure transducers or water level indicators before, during, and after pumping tests.

Q4: Can well efficiency change over time?
A: Yes, well efficiency can decrease over time due to factors such as screen clogging, mineral deposition, or changes in aquifer conditions.

Q5: How can well efficiency be improved?
A: Well efficiency can be improved through proper well development, rehabilitation techniques, optimal screen design, and appropriate pumping rates.