Guide to Florida Lawn Irrigation
Why is sprinkler repair something that you should be concerned with? For instance, Lake Mary FL is a semi-tropical environment and most of the plants used in outdoor landscaping require supplemental watering at some point during the year. The most convenient way to accomplish this is through the use of an automatic sprinkler system. In fact, most homes and commercial buildings are constructed with an irrigation system in place at the inception of occupation.
Sprinkler System Equipment
Like all complex systems, sprinkler systems need regular maintenance in order to function correctly year around. Here is a brief rundown of the system parts and the problems associated with their functions.
Backflow Prevention
A backflow is a mandatory device for any water delivery system that supplies water for both the indoor plumbing and outdoor watering. This applies to potable city water and pump and well systems. What a backflow does is prevent the system from siphoning water through the pipes and heads from getting into the potable water system in the case of back siphonage. Local municipalities, like Sanford can set their own backflow regulations as long as they meet or exceed the State of Florida requirements. For Seminole County, you can view their requirements here. It is at this device where you would commonly turn off the water to the irrigation while maintaining water flow to the building, so it is a good idea to know where it is.
Irrigation Timer Controller
Often referred to as the “brain” of the system, the controller regulates the time and duration that the various sections or “zones” run. All controllers are programmable; however digital controllers offer more flexibility than mechanical controllers. How do you know which type you have? A digital controller will have a screen that tells you the time of day. Most digital controllers include a backup battery that will hold the program in place in case there is a temporary power outage. This battery should be replaced every year.
All counties in Florida have watering regulations that specify which days and during which hours you are allowed to water the landscaping. Sprinkler repair companies will have this information and can program your controller for you based upon your location. If you do this yourself, just search for your county with the term “water restrictions.” For example, here are the watering restrictions for Lake Mary. There are exemptions for low volume or “drip” systems, so please read the documents carefully, as being in violation can cost you a fine.
Automatic Sprinkler Valves
If the controller is the “brain” of the automatic irrigation system, then the valves are the “heart.” The valves rest in the normally closed position until the controller tells them it is time to open (via the solenoid) and let the water from the mainline pipe flow through to operate the sprinkler heads. The reason for valves and zones is that your water meter or pump cannot produce enough water to irrigate your entire property all at once. Therefore your landscape is divided into sections that run separately from each other. However, that is not the entire reason.
Another reason is that different types of sprinkler heads put out different amounts of water per minute per foot of area covered. For instance, a fixed head spray watering a 15 foot, 180 degree area will normally have a precipitation rate of 1.5 gallons per hour over its coverage area. A rotor (the heads that turn and spray longer distances) with a 3 gpm nozzle will have roughly a precipitation rate of .5 gallons per hour, or one third that of the spray head. Because of this the rotor head needs to run three times longer to put out the same amount of water, thus needs to be zoned separately from the spray heads.
It is a good idea to have an “as built” plan showing where the valves are buried. If a valve stops opening or won’t shut off you will need to find where it is located.
Drip irrigation needs to run for much more time than either the spray or rotor zones so it also must run separately. Other considerations for dividing your sprinkler system into zones are micro climates. If you have a spray zone that covers only a shaded portion of your yard, the plants in the shade will require less water than those in the full sun and need to have that zone run time shortened.
Problems with failing valves arise from three basic scenarios:
The valve will not open
The valve will not close
The valve leaks, or “weeps”
There are many reasons why any of the above issues may happen. For a more in depth look at these problems individually, I suggest visiting https://edis.ifas.ufl.edu/wi005 or calling a Central Florida irrigation contractor. Remember; never open a valve that is under pressure as you could be injured.
Sprinkler Heads
Sprinkler head repair is a complex subject due to the variety, types and brands available. Many have very specialized functions and there are no “one size fits all” solutions. Also, different brands have different precipitation rates, and the main objective of every zone is to achieve irrigation uniformity. Our suggestion for those who want to repair their own sprinkler heads is to replace the broken sprinkler with the exact make, model and brand that was there originally. That said, here are some general considerations.
If a spray head stops working it is probably the nozzle. The nozzle contains the orifice which delivers the water. These often become clogged and need to be replaced. There is a wide array of nozzle sizes and patterns. The nozzle you replace should match the old one exactly. The type and size of the nozzle will be printed on top. If you are unsure just take the old nozzle to the hardware or irrigation supply house and they will give you the right one. Don’t forget to also replace the screen which helps filter any dirt in the water before it reaches the nozzle.
If an enclosed gear drive rotor stops turning, it is broken and should be replaced. This does not apply to older style Rain Bird type impact rotors. Pop up impact rotors expose their internal mechanism to yard dirt and debris which is why they have fallen out of favor with installers. If an impact stops turning it often has debris in the springs which you can clean out by hand.
All types of sprinkler heads in the ground should be attached to the PVC pipe using a “swing joint.” This is normally a 12 inch piece of flexible hose, but can also be assembled from threaded nipples. The reason for the swing joint is to keep the PVC from being damaged or broken if the sprinkler is run over by a car or heavy zero turn mowers.
Mixing Types of Sprinkler Heads
Do not mix rotors and sprays on the same zone. We covered this above but it cannot be overstated. If your system currently has mixed types of sprinklers, an evaluation and possible redesign is in order. When replacing broken sprinklers or repairing pipe in the ground, always dig a hole much wider and deeper than you might first think necessary. The reason for this is to keep dirt and debris out of the sprinkler pipe. Have a small cup or container with you when you unscrew the head so that you can bail water out of the hole before any mud can get in the open pipe.
