Automatic Irrigation: Planning and Installation

Automatic irrigation delivers the water plants need at the right time and uses less than hand watering. It should be planned before hard landscaping is built.

In a hot summer, watering a garden by hand means hours with a hose every evening. Go on holiday and plants dry out within days. An automatic irrigation system takes over this job, but its real value goes beyond convenience: a well-planned system gives each group of plants as much water as it needs, preventing waste and puddles. To achieve this, the system must be designed together with the garden layout, at the earthworks stage.

Water source, pressure and flow

The water source sets the system's limits. It can be mains water, a well, a rainwater tank or a combination. Two figures are measured before planning: pressure and flow rate, meaning how much water the source can deliver at a given pressure.

This shows how many sprinklers or drip lines can run at once. If the source is weak, the system is divided into more zones that run in turn. A tank or well needs a pump and a pressure vessel. When connected to mains water, a backflow prevention valve protects the drinking water supply from contamination.

Dividing into zones

Plants in a garden have different water needs, so they should not all be watered the same way. These zones are usually defined:

• lawn: with sprinklers, for even coverage;
• flower and shrub beds: with drip lines close to the roots;
• trees: with drip rings around each tree;
• vegetables and herbs: separate drip lines on a different schedule;
• pots and containers: micro-drip emitters.

Sunny and shaded areas are also split into separate zones, as soil dries more slowly in shade. Each zone has its own valve, and the controller programmes them separately.

Sprinklers and drip irrigation

Sprinklers are the main solution for lawns. Pop-up heads that rise under pressure and retract when watering ends do not get in the way of mowing. Heads are spaced so each one's throw reaches the neighbouring head; otherwise dry strips remain at the edges. Sprinklers should not throw water onto paths, facades or windows.

Drip irrigation delivers water directly to the root zone. Losses to evaporation and wind are low and leaves stay dry, which reduces the risk of some plant diseases. Drip lines can be hidden under mulch. In hot, dry climates, drip irrigation is especially efficient for flower beds, shrubs and trees.

Control and sensors

The controller sets watering days, start times and durations for each zone. The best time to water is early morning before the day heats up: evaporation is low and plants start the day with moisture. Prolonged dampness at night can raise the risk of fungal disease in some plants.

A rain sensor stops the system running during or after rain. Soil moisture sensors match watering to real need. Some controllers adjust the schedule automatically based on weather data and can be operated from a phone.

Installation sequence

• Zones, heads and pipe routes are drawn on the garden plan.
• The main supply pipe and valve boxes are laid before paths and terraces are paved; protective sleeves are used where lines cross under paths.
• Valve boxes are placed where they are accessible for maintenance but unobtrusive.
• A filter and pressure regulator are fitted, particularly at the start of drip lines.
• The system is tested and head coverage checked before the lawn is laid.
• A power point for the controller is provided in a dry, protected place.

Seasonal maintenance

When the system is started up in spring, heads are cleaned, damaged parts replaced, filters rinsed and the schedule adjusted to the weather. During summer, head directions and drip emitters are checked periodically for blockages. Where there is frost, lines are drained or blown out with air before winter, since freezing water can burst pipes and valves.

Zaferoğlu İnşaat routes irrigation lines during yard works before paths and terraces are built, so finished paving never has to be lifted to lay pipes. Have your supply pressure and flow measured, and those two numbers will tell us together how many irrigation zones are possible.