Optimal horsepower for deep wells — what’s necessary?

Sizing a Deep Well Pump

When sizing a deep well pump, it’s essential to consider the well’s static level and the desired water pressure at the surface. A general rule of thumb is to use a pump with a horsepower rating at least 10% higher than the calculated horsepower required based on the well’s yield, depth, and diameter. For example, a 500-foot well with a 6-inch diameter and a 50 GPM yield would require a pump with a minimum of 12 horsepower.

Well Yield and Depth Considerations

The well’s yield and depth are critical factors in determining the required horsepower. As a general guideline, a 10-foot increase in well depth typically requires an additional 1 horsepower. Additionally, a well with a higher yield will require a more powerful pump to maintain a consistent pressure at the surface. For example, a well with a yield of 100 GPM at 500 feet may require a pump with 20-25 horsepower, while a well with a yield of 50 GPM at the same depth may require only 10-12 horsepower.

Factors Affecting Horsepower Requirements

Other factors that can affect horsepower requirements include well diameter, casing size, and pump type. A larger well diameter or casing size may require a more powerful pump to maintain a consistent flow rate and pressure. Additionally, the type of pump used can also impact horsepower requirements. For example, a jet pump may require less horsepower than a submersible pump for the same well yield and depth.