The water pump is the heart of any irrigation system, including drip irrigation, sprinkler irrigation, subsurface drip irrigation, and other irrigation types. It supplies water to gardens, farms, landscapes, and golf courses. To make an irrigation system as efficient as feasible, you should choose the pump that meets the needs of the water source, the water distribution system, and the irrigation method.

Selecting the right irrigation pump leads to efficient water application and long-term savings. It ensures that water is delivered properly to where it is needed. But how can you choose the right pump for your irrigation needs? This guide will help you select the best pump for optimal irrigation.

Learn about the common types of irrigation pumps and how to choose the right one for your drip irrigation system.

Common Types of Irrigation Pumps

Irrigation pumps come in various types, each with its own set of features, benefits, and drawbacks.

Centrifugal Pump

Centrifugal pumps work by using the centrifugal force of a rotating impeller to create a water flow. The impeller draws water into the center and then slings it out again. This mechanism increases the water speed and creates pressure to move water through the tubing or pipe. Centrifugal pumps are the most common, less expensive, and easier to maintain than other pumps. They are commonly used for lawn irrigation and pressure-boosting applications where the pump is only used occasionally.

Features: Best for garden irrigation, lawn irrigation, and small to mid-sized farms

Pros

• Affordable and commonly available
• Suitable for large volumes of water at reasonable pressure

Cons

• Not suitable for deep wells

Submersible Pump

Submersible pumps are partially or fully submerged in the water. They are designed to be placed underwater and are commonly used in deep wells. The water keeps the pump cool and allows it to run continuously for a long time. These water pumps are preferred for their water features and applications where they can be used continuously. Submersible pumps have a greater lifespan and are more efficient than other types of pumps.

Features: Best for deep wells and operates underwater

Pros

• Highly efficient
• Able to push water to the surface
• Quiet operation
• Longer lifespan

Cons

• Expensive
• Difficult to maintain

Jet Pump

Jet pumps are used to pump water from wells where the water level is too low for other pumps to work. This irrigation pump uses a jet device to lift water below the pump level which is a common issue for centrifugal pumps. They generate a high-speed jet of water which creates a partial vacuum and draws water up through a pipe. However, they have a lower flow capacity than other pumps.

Features: Can be used for shallow and deep wells

Pros

• Versatile
• Best for lifting water from depths
• Can handle different water levels

Cons

• Complex design
• Higher maintenance
• Less efficient than a submersible pump

Factors to Consider When Selecting an Irrigation Pump

Water Source

The type of water source you have will impact the pump you need. Common sources include shallow wells, deep wells, rivers, ponds, lakes, and municipal water systems.

Power Source

Depending on your location and needs, you can choose between petrol, electricity, diesel engines, or solar energy. Electric pumps are the most convenient and simple to maintain, but they may not be appropriate if you live in a remote area or if the electricity supply is irregular due to power outages. Petrol and diesel-powered pumps can handle large amounts of water, but they are typically more expensive and require greater maintenance.

Total Dynamic Head (TDH)

It refers to the vertical distance water travels plus the friction loss from the pipe. You need to ensure that the pump can lift the water pressure to the pressure required for your irrigation system.

Water Horse Power (WHP)

WPH is the power required to operate the pump.

Water Flow and Pressure (PSI)

The PSI indicates the amount of pressure that the pump can generate. Your pump must provide sufficient pressure to transfer water throughout your irrigation system. Make sure to select a pump that can meet the needs of your irrigation system. Centrifugal pumps are ideal for low- to medium water flow applications.

Maintenance and Durability

Consider pump designs that are easy to maintain and long-lasting. Choose pumps made from high-grade materials for durability, such as stainless steel or ductile cast iron, especially for unsheltered areas. Also, consider your budget, pump operation cost, and after-sales service.

Crucial Steps for Selecting and Sizing an Irrigation Pump

Here are the steps to choose the right pump for your irrigation system.

1. Choose the Right Pump Type

To select the best pump for your irrigation needs, first determine the type of water source you have. The choice of pump depends on flow rate, water depth, and source type. Match the pump type to your water source so your irrigation system performs optimally and efficiently.

• For water source up to 25 feet deep: Centrifugal pump or shallow well jet pump
• For a water source between 25-110 feet deep: Deep well jet pump
• For water source deeper than 110 feet: Submersible pump
• For municipal water system: Centrifugal pump
• For lakes, ponds, streams: Centrifugal pump, submersible pump

2. Determine your Water Requirements

Calculate the following to determine specific water needs:

CWN = The amount of water your crops need daily

TWR = Gallons of water required per day

IOT = Number of hours the irrigation system will run

Review system documents and check GPM Specifications

3. Calculate the Flow Rate

Flow is measured in gallons per minute, GPM.

Find the Required GPM

Assess your system's needs and determine the required GPM through this formula.

GPM = TWR/IOT/60

Verify the Flow Rate

Make sure it is GPM. An accurate flow rate calculation allows you to choose a pump that delivers the appropriate amount of water to your irrigation system.

4. Confirm the Pressure and Elevation

Assess the pressure required at all entry points of your irrigation system. Then, measure the total vertical distance (head) between the water source and the highest point of the irrigation system.

Consider friction losses, which pressure loss due to friction in the pipes and fittings. Next, consider the suction lift, which is the vertical distance between the water level and the pump inlet.

5. Calculate Pressure

Calculate the (TDH) Total Dynamic Head to guarantee that your pump can handle the pressure requirements of your irrigation system and work optimally.

TDH = Suction Lift + Static Head + Friction Loss + Required PSI

6. Confirm GPM and TDH Measurements

To choose the best pump for your irrigation system, look at the manufacturer's performance curves. These curves indicate how well a pump works at various flow rates and pressure levels. Then, match the pump's features to your system's required GPM and TDH measurements to ensure it meets your system's requirements.

This step will help you select a pump that provides optimal performance and efficiency for your irrigation system.

7. Compare Different Pumps and Choose the Best One for Your Needs

Finally, to choose the best pump for your irrigation needs, compare different pumps based on performance to confirm they meet your flow rate and pressure specifications. In addition, choose a pump that functions around its Best Efficiency Point (BEP) for optimum performance and energy savings.

Evaluate other factors such as ease of maintenance, durability, and warranty. Consider your budget and long-term operational costs, and choose a pump that fits your budget.

The Bottom Line

Choosing the right irrigation pump plays a key role in the success of your irrigation system. When selecting pumps for garden or small farm irrigation, you can choose centrifugal pumps. They are commonly used in irrigation and other industries due to their simple design, low friction loss, and low risk of leaks. Submersible pumps are also effective for home and commercial applications.

Carefully consider your unique needs and requirements and then make an informed decision to ensure efficient irrigation for better crop output. A poorly chosen irrigation pump or irrigation method can lead to water wastage and increased costs. Careful evaluation of the above-mentioned factors helps you select a pump that is reliable, durable, efficient, and cost-effective.