How to Plan a Sprinkler System Layout
plan a sprinkler system layout, the very first thing you need to do is
create watering zones. Flowers, plants, bushes, trees and lawn each have
there own water demands. You should group together flora with similar
demands into a zone. This
is referred to as hydrozoning. For instance your lawn will require a certain number of gallons of water, delivered over a certain number of minutes on a certain number of days. Flower beds will require a different watering schedule than the lawn and so should be in a separate watering zone. This allows you to water the two zones with different schedules and for different lengths of time. Other plants will have their own watering requirements and so so should be grouped for similarities in their water needs. Finally, if a zone is too large, the water supply will not be adequate to provide proper pressure to all of the sprinklers. In that case, a zone must be split into two or more zones to ensure adequate water pressure.
Next, you need to select the type of spray head you prefer. There are three basic types: Spray heads, rotor heads or drip systems. The primary difference between the three concerns application rate, gallons per minute of water delivered (GPM).
Spray heads yield a high volume of water in a short period of time; the average application rate is 1.5 to 1.7 inches per hour. Spray heads either pop up from underground when the system is activated, or they sport stationary heads on a pipe fitting above ground. Spray heads work best on small areas, such as flower beds, shrubs or turf; they are also best suited for flat lots and sandy soils. If used on sloped lots or clay soils, the large amounts of water being delivered don't have time to soak in. A series of short watering times with pauses between will give the water more time to soak in. The common spray patterns are quarter, half or full circles; although they can also be arranged to cover rectangle and square areas.
Rotor heads are best suited to large areas, and they apply water more uniformly than do spray heads. They have a lower application rate of 0.6 to 0.8 inches per hour; the slower application rate is well suited to all soil types and requires less cycling. Rotor head styles include impact or gear-driven. They spray in partial or full circles, and they can be adjusted to various angles.
Drip systems are handy for watering flower beds. A drip system is simply a small hose with holes or emitters along its length. Emitters can be spaced to cover closely-spaced beds or precisely positioned to water specific plants. Drip systems are consider good choice because they apply water directly to the soil, eliminating runoff. They keep water off of the plants leaves and flowers, reducing the risk of damage and disease. Drip systems also feature widely varying application rates, from 0.5 to 24 gallons, which renders them easy to adapt to any soil type and a plants particular needs..
When deciding which type of system is appropriate for your needs, you should also keep in mind the height of your plants. You don’t want a system whose jets of water will smack your Asian lilies in the face, causing their petals to fall off. Your system should also be zoned, as shady areas may require less water than full-sun areas.
Once you have selected the type of sprinklers, you can plan the layout and calculate the water demand by zone. If the demand exceeds the water supply, you will have to rethink your design and get the demand equal to or lower than the supply.
Next you can layout the pipes for your plan. Minimize the number of feet of pipe and the number of sharp bends because this both reduce the water pressure. To many bends can dramatically reduce your water pressure to inadequate levels.
systems can be equipped with handy automatic timers. However, don’t
let the crutch of an automatic timer trump your common sense. Once
you install your sprinkler system:
- Don’t water immediately preceding, during, or after a rain!
Or better yet, select a timer with a rain sensor.
- Water only during dawn or dusk. Water evaporates
rapidly during the hottest hours of the day; this doesn’t provide
your plants with the quenching drink they need, and the mix of water
and hot sun can damage their leaves.
- Adjust your watering cycle to the seasons. You won’t
have to water as often in spring and fall when rain is more frequent.
- Listen to the land. If the ground can’t readily absorb
the water and creates runoff, decrease the duration of the cycle. More
frequent, but shorter, cycles may be necessary, especially for clay
You should also follow the manufacturer’s recommendations for
proper winterizing. If you leave in a winter freeze climate, it’s
advisable to hire a landscape and irrigation expert to blow all the
water out of the lines in late fall to prevent winter freezing.
The proper sprinkler layout will save you loads of time--so you can
sit back and admire your yard!