The Anatomy of Your Irrigation System

With another hot Central Texas summer around the corner, irrigation systems are more important than ever to keep your landscape watered, green and healthy. The experts at Silicon Hills Irrigation have the knowledge and experience to design the perfect sprinkler system for your needs or provide quality sprinkler system repair.


Learn more about the components that make up an irrigation system and the ways Silicon Hills Irrigation implements these components to create an efficient, cost-effective, and water-wise solution for your home.

From the Water Source to You

Water is delivered to both your home and irrigation system from a water source, such as a municipal water main, a well, or a surface water source like a drainage pond or reservoir. As water passes from the source through a supply line, a water meter measures and records the volume of water flowing through the pipe to your property.


Between the water meter and your home, a connection is made to supply water to the irrigation system. The water that is diverted for your irrigation system then flows through a ball valve, also known as an isolation or shutoff valve. This valve serves as the main shutoff for an irrigation system and is used to close off water flow in the event of an emergency or the need for maintenance or repair to the system without affecting the water supply to your home.

Protecting Your System and Drinking Water

A Y-filter, or strainer, installed after the isolation valve, helps to protect the irrigation system from impurities that may cause the sprinkler heads or other components to clog or become damaged over time. The Y-filter filters out particles, such as sand or silt, and is essential for efficient operation and a long life for your irrigation system.

In addition to protecting your irrigation system as a whole, the Y-filter is also critical for keeping particles out of the backflow preventer, ensuring that it is able to close. As you learned above, the water used for your irrigation system is connected to the water flowing to your


home through a cross connection, where it is possible for non-potable substances to come into contact with your drinking water supply. To prevent this contamination, the backflow preventer, installed right after the Y-filter, stops water from flowing backward, ensuring the water entering your home is completely safe and potable.

There are multiple types of backflow preventers, and use depends on local building codes. Silicon Hills Irrigation primarily utilizes double check valves, which contain two independent valves that operate even if one of the two is jammed or fails, allowing for a more reliable seal that avoids even the most minor leakage. When required for higher hazard levels, we also utilize reduced pressure zone devices that work like double check valves with the addition of an intermediate relief valve that operates if both valves should fail.

Pressure Regulation

After the water for your irrigation flows through the backflow preventer, it travels through a pressure regulator designed to limit excessive inlet water pressure and provide a constant outlet pressure. In other words, if water passes through the regulator at a high pressure, the excess pressure forces the device to close just enough to maintain the desired pressure and flow. This ensures the sprinkler heads or drip lines provide a uniform, consistent application and correct droplet size.

The Heart of Your Irrigation System

After passing through the pressure regulator, the water reaches the irrigation system’s master valve. This valve is connected to the irrigation system controller and remains closed until the controller sends a signal that activates the solenoid that allows the valve to open. The solenoid, a magnetically controlled coil component within the master and zone valves, uses the electrical signal to physically open and close and control the flow of water. The master valve is critical for preventing water loss and leaks from the mainline when the system is not operating.

Pipes and Emitters

The mainline of your irrigation system is the main pipe that feeds all of the zone valves. The pipe is buried eight to 12 inches below the surface in trenches that are dug slightly deeper during your sprinkler installation. Silicon Hills Irrigation utilizes pipe made of polyvinyl chloride, also known as PVC, which works well for warmer weather climates.

Much like the main master valve, the zone valves of your irrigation system remain closed until the controller sends a signal to the solenoid within each valve to open and begin operating. These secondary valves are located in each of the zones, or stations, of your irrigation system. When a zone valve receives a signal to operate, it releases water into the zone to the sprinkler heads or drip tubing. At the end of the runtime, the controller sends a signal to the valves to close and cease operation.

When a valve opens and releases water into a zone, the pressure of the water activates the emitters: the sprinkler nozzles (also known as sprinkler heads) or drip tubing.


Spray nozzles

  • spray nozzles, which are typically used for smaller areas, deliver a fixed water pattern of droplets or fine mist.

  • For larger areas, rotor nozzles use a rotating stream or multiple streams and rotate left and right to apply water to the entire area.

  • Tree bubblers are small nozzles designed to bubble over and cover the ground surface around a tree.

  • Risers are used to elevate an emitter above the ground, often to water larger plants and shrubs.


While sprinkler heads work well for lawn irrigation and watering larger areas, drip irrigation provides a great solution for flowerbeds and vegetable gardens. Drip irrigation utilizes above-ground tubing, also known as a drip line, to slowly emit a precise amount of water directly to the root zone where plants draw in water and nutrients. This efficient method conserves water by eliminating run-off and water waste due to evaporation, wind, or overspray mist.

The Brain of Your Irrigation System

How does your irrigation system know when to operate? A controller, sometimes referred to as a sprinkler timer, sends electrical impulses to the valves to open or shut. The controller is typically a wall-mounted device and can be programmed to turn on automatically at desired times, making your life easier and your watering more efficient.

In addition to the programmable controller, a wall-mounted rain sensor is installed to save you money, conserve water, and extend the life of your irrigation system. The rain sensor detects when it is raining and communicates with the controller to skip the next cycle. In the event that rain begins while the sprinkler system is running, the rain sensor communicates with the controller to stop the signal to the valves, causing the system to shut off. Silicon Hills Irrigation utilizes expansion disk rain sensors that operate via a gauge containing disks that absorb water and expand. The signal that turns on the irrigation system remains blocked until the disks shrink back to their original, dry size. In additional to sensing rain, these sensors also detect freezing temperatures, helping to reduce vegetation damage and icing conditions.

Contact Us to Learn More

Each part of your irrigation system plays an important role in keeping your lawn, flowerbeds and gardens healthy. Contact Silicon Hills Irrigation to learn how we use quality components and expert design to create and install systems that save you money and provide efficient, worry-free irrigation.