Step-by-Step Guide

Understanding the Low Pressure Problem

Low water pressure can cause significant irrigation inefficiencies, particularly for large rotor zones. When pressure drops, rotors fail to achieve full coverage, resulting in poor distribution uniformity (DU). This means water gets dumped in the wrong places rather than being spread evenly across the entire irrigation circle, ultimately wasting water.

Pressure drops can occur at random times for various reasons, including water being siphoned off the main line for other purposes such as filling tanks, cooling systems, or other uses when there isn't a dedicated irrigation main line. While spray zones, small rotors, and drip systems may operate fine at lower pressures, large rotor zones are particularly vulnerable to pressure fluctuations.

Solution Overview

Rather than attempting to boost pressure or control other water uses, the solution is to automatically pause irrigation when water pressure drops below an acceptable threshold, then resume watering when pressure is restored. This approach ensures that zones receive their full required runtime—just not during periods of low pressure when irrigation would be inefficient.

For example, if turf needs an hour of water, it will still receive that full hour. The system simply won't water during periods when low pressure would result in poor coverage.

Required Equipment

Only two components are needed to implement this solution:

• A quarter-inch connection to the main line
• A pressure monitoring device—either a 5406 Pressure BiCoder kit or a ControlPoint PFS (which includes a flow sensor, pressure transducer, and master valve BiCoder)

Once these components are installed, all programming is handled through the controller.

Organizing Zones into Programs

Before setting up the pause condition, ensure all high-pressure rotor zones that are affected by low pressure are grouped together in the same program. Do not mix these zones with other zone types (such as spray zones or drip zones) that aren't affected by pressure drops. This allows you to apply the pressure-based pause condition to only the zones that need it, without impacting other irrigation.

Creating the Pressure-Based Pause Condition

1. Navigate to the program that contains your high-pressure rotor zones and select Edit.

2. Verify that your zones are properly configured with:

• Runtime settings
• Run days
• Schedule settings
• Water window (if applicable—though this may not help if pressure drops are unpredictable)

3. Select Add a Condition. Conditions can control when a program starts, stops, or pauses.

4. Choose Pause Condition rather than a stop condition. This is critical: a stop condition would clear all remaining runtime as soon as pressure drops, meaning zones wouldn't run again until the next scheduled start time. A pause condition preserves the remaining runtime and resumes irrigation where it left off.

5. Configure the pause condition settings:

• Select Pressure as the condition type
• Choose the correct pressure sensor from the list
• Set the pressure threshold (for example, 50 PSI or 60 PSI—whatever threshold your rotors require for proper operation)
• Set the pause duration (for example, one hour)

The complete condition reads: "When the pressure drops below [threshold] PSI, pause for [duration]."

How the Pause Condition Works

When water pressure drops below the configured threshold, the affected program immediately enters a paused state. The program status changes from green (running) to magenta (paused), similar to how programs appear during a water source pause.

The program remains paused for the configured duration (for example, one hour). 

At the end of that period, the system checks the pressure again:

• If pressure has returned above the threshold, the program resumes irrigation exactly where it left off—mid-zone if necessary
• If pressure is still below the threshold, the pause period resets and the program pauses for another full duration

This means a program could potentially pause for multiple consecutive periods. For example, with a one-hour pause setting, if pressure remains low for 90 minutes total, the program would pause for one hour, check the pressure, find it still low, pause for another hour (now 2 hours total), then check again 30 minutes later and resume when pressure is restored.

Impact on Other Programs

The pause condition only affects the specific program to which it's applied. When a program enters a paused state due to low pressure, it's essentially sidelined—not actively running. During this pause period, other programs that don't have pressure-based pause conditions can run normally.

This is why it's important to separate zone types into different programs. For example, drip zones that aren't affected by low pressure can continue running in their own program even while the high-pressure rotor program is paused. The low pressure condition won't impact drip program operation because those zones are in a separate program without a pressure pause condition applied.

Adjusting Pause Duration

The pause duration can be adjusted based on your site's specific conditions. If you know approximately how long pressure drops typically last, you can set a shorter pause period (such as 15 minutes) to check pressure more frequently. The system will continue checking at each interval until pressure is restored, at which point irrigation resumes automatically.

Video Walkthrough

Video originally published December 2022.

If you have questions, here are 3 ways to get answers:

1. Search within this HydroPoint knowledgebase

2. Visit the HydroPoint support page

3. Call 800-362-8774 or email support@hydropoint.com, hours are Mon-Fri 3:00 AM – 6:00 PM PT and Sat 9:00 AM – 2:00 PM PT.