Measuring Your Water System Pressure

To measure the pressure available for your drip irrigation system, you typically measure the pressure of your main water source.

Here is how you measure drip irrigation pressure by checking your system's source pressure:

Understanding the pressure of your water source is the first step in designing and operating an efficient drip irrigation system. This is the pressure that flows from your main water line or well.

According to a common method for assessing system capacity, you can measure this pressure directly:

• Attach a pressure gauge directly to a water spigot that is representative of the pressure supplied to your irrigation zone.
• Before taking the reading, make sure all other water sources in your home or property that use the same main line (like sinks, showers, washing machines, etc.) are shut-off. This ensures you measure the maximum static pressure the system can provide without flow diversions.
• Turn on the spigot fully.
• Read the gauge to get the pressure value.

This measurement indicates the pressure your water system provides.

Why Source Pressure Matters for Drip Irrigation

Drip irrigation components, such as emitters and drip line, are designed to operate efficiently within specific pressure ranges.

• Too High Pressure: Can damage components, cause emitters to spray rather than drip, or lead to excessive water use and unequal distribution. Pressure regulators are often needed if the source pressure is above the recommended range (typically 10-50 PSI for most drip systems).
• Too Low Pressure: Can result in insufficient flow, uneven watering across the zone, and drippers failing to emit water correctly.

Knowing your source pressure helps you select the right components and determine if a pressure regulator is necessary.

Practical Steps for Measuring Pressure

Here’s a simple breakdown of the process:

1. Obtain a Pressure Gauge: You'll need a standard water pressure gauge, often available at hardware stores. Look for one with a garden hose thread (GHT) connection. They usually measure in Pounds per Square Inch (PSI).
2. Locate a Spigot: Choose an outdoor spigot or other connection point that reflects the pressure supplying your irrigation area.
3. Prepare the System: Shut off all other water-consuming fixtures inside and outside the property.
4. Connect the Gauge: Screw the pressure gauge onto the spigot connection firmly by hand.
5. Turn on Water: Open the spigot valve completely.
6. Read the Gauge: Observe the needle on the gauge to determine the water pressure reading in PSI.
7. Record the Reading: Note down the measured pressure.

This measurement gives you the static pressure your water system provides at that point, which is the baseline for your drip irrigation design.

Measurement Details

Here is a summary of the process:

Step	Action	Purpose
1. Preparation	Shut off other water uses	Measure full static pressure
2. Connection	Attach pressure gauge to a spigot	Create a point to read pressure
3. Activation	Turn on the spigot fully	Allow water flow to the gauge
4. Reading	Observe the gauge needle	Determine the pressure value
5. Result	Note the value (e.g., 55 PSI)	Identify the system's provided pressure

This simple measurement is fundamental for setting up an effective and durable drip irrigation system.