Ottawa Irrigation 101
How an automatic irrigation system works: This first blog post is quite long, but I wanted to include all of the essentials to give you a much better idea about how an automatic sprinkler system works and some of the factors that are considered during design. This will give you a better idea of what is going on with your irrigation system, and what you can expect after the installation of your sprinkler system. You will be taken through the different types of automatic sprinklers and essential components used in a system, and some key terms and concepts like water pressure, flow rate and valve zones.
Design: the design of an automatic irrigation system begins with checking the water output (pressure and flow rate) of the source water you that will be used for your landscape watering; as well as a survey of your landscape.
Checking the water pressure and flow rate is necessary in determining the amount of sprinkler heads that can be installed on each valve zone for optimal performance. This allows the number of valves zones that are required to be calculated. An irrigation system is split into different valve zones so that each sprinkler head distributes water efficiently. For each additional sprinkler head in a zone, water pressure will be reduced at each sprinkler. This affects its performance and efficiency. Thus the determination of the correct number of sprinkler heads per valve zone is very important so that the zone will be operating at an optimal pressure for maximum efficiency. The water flow rate is important to determine how much water will be provided to the area. This is used for determining the watering duration of each zone in order to provide sufficient water at each watering time.
Separate valve zones are also used for different areas of your landscape because they have different watering requirements. By zoning these areas separately, it allows control of the watering duration as well as time of day to be programmed into the controller.
A different type of sprinkler head will be used depending on whether the area being watered is a large or small area of your lawn, shrubs, flowers, or gardens, etc. Each different type of sprinkler head requires a different water pressure and flow rate to achieve the desired spray. The correct numbers of sprinkler heads is determined and they must be placed strategically in order to provide full coverage to each zone.
Sprinklers: the three main types of sprinklers are rotors, pop-ups, and risers:
Rotors: the large sprinklers used to water the lawn. As the water is turned on, these sprinklers pop up out of the ground and operate by spraying water in a rotating fashion covering the desired area. The degree of rotation can be adjusted, as well as the flow rate and distance of spray by the use of different nozzles in the sprinkler.
Pop-ups: these smaller sprinklers pop up out of the ground during operation. The spray is controlled by using a specific nozzle that controls the water flow rate as well as the angle of spray. They are mostly used for watering flower beds and other small grass sections of your lawn.
Risers: these sprinklers consist of a nozzle mounted on a long, thin tube (usually 12 or 18 inches) and do not retract into the ground. These sprinklers are mostly used for watering taller shrubs and bushes. Like the pop-ups, watering is controlled by the type of nozzle.
Installation: Once the design and placement of the sprinklers is determined, the construction of the system begins.
The first step is the plumbing. This involves tapping into the water source. The water source for most urban residences is the same city water that is supplied to your home; and that for rural residences will either be the well water source or can be pumped from a nearby lake or river. After tapping into the water source in your home, we will drill a hole to the outside to connect the source line to the main valve.
Backflow Preventer: This device is used in ever irrigation system and is the essential component of safety. This device prevents any water in the sprinkler system from flowing back into your home and into your waterline. It is connected between your water line and the main valve.
Valves: all of the valves are solonoid valves which function pneumatically. The water flow is controlled by a solonoid that receives an electrical signal and converts the energy into mechanical energy to open or close a diaphragm (thus turning the water flow on or off, respectively).
Main Valve: the heart of the system. This valve controls the water flow to all of the other valves in the system. Each time watering is to take place; this valve is opened and allows water to flow through the main line to all of the other valves.
Control Valves: each secondary valve controls the flow of water to the specific zone it is feeding. The valves are opened one at a time in order to water each zone individually, so that enough water pressure is present to water the entire area of that zone.
Automatic Controller: the brain of the system. This controller provides an electrical signal to each specific valve at a specific time in order to allow water of each zone at a time and duration chosen for optimal and efficient watering. The controller operates digitally and is very simple to program. We will take care of the initial programming of the controller for optimal watering.
Pipes: All pipes used with a diameter of less than 1.5 inches are polyethylene pipe. If over 1.25 inch diameter, pvc pipe will be used. The pipe is installed underground at depths of 6-10 inches where as the ground conditions allow it. This is done by either digging a trench, or using a pipe pulling machine (vibratory plow). This is done in a careful manner where the grass is removed, a trench is dug, and then the grass is placed back over the trench, tamped and raked. You won’t even know there is a pipe under the ground.
Rain Sensor: this device overrides your program to prevent overwatering when it rains. Essentially if it is raining during a watering time, the rain sensor will turn off the system, essentially ensuring that no unnecessary water is used.
Once the entire system is built and connected, it is tested to ensure complete watering coverage to each zone and area of your landscape.
Stay tuned for the next post describing what you can expect during our visit to your Ottawa home to provide you with a free automatic irrigation system estimate.
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