Design a Drip Irrigation System

Getting Started

Compared to conventional sprinkler systems, drip irrigation systems are simple to design, inexpensive, and easy to install. Traditional high volume, high pressure sprinkler systems require careful planning, extensive trenching, and special tools and glues. Drip irrigation systems can be easily installed above or below ground, without special tools and glue or extensive technical knowledge. These efficient systems deliver water measured in Gallons Per Hour (GPH), and apply water only where it is needed. This can improve plant health, conserve water, and reduce the growth of weeds all at the same time. In addition, drip irrigation can reduce disease problems associated with moisture on the leaves of plants.
home residance drip irrigation system

Adjustable drippers or micro sprinklers

PC button drippers to shrubs

Drippers or misting sprayers for hanging plants

4- or 6- outlet drip heads or 12-Outlet Maverick™ to retrofit 1/2" riser

Micro sprayers for flowerbeds

Brown PC Dripline or drip soaker tape for a vegetable garden

Planning and Designing a Low Volume Irrigation System

When designing an irrigation system we first recommend considering the various areas and plants to be watered. We suggest using drip irrigation on trees, shrubs, vines, vegetables, flowerbeds, containers, pots, boxes, house foundations, on any individual plant, and narrow planting areas. Micro sprinklers are best used on groundcover, flowerbeds, groups of plants, hillsides and on very sandy soil. In sandy soil water will percolate downward when using drip before it can spread far enough horizontally; micro sprinklers will solve this problem because of the wide spray diameters. Avoid using micro sprinklers in windy areas. High winds will disturb the micro sprinkler spray pattern.

CREATE A PLANT LIST ( download our pdf graph )

First, note and list the locations of small and large trees, shrubs, groundcover, flowerbeds, containers and vegetable gardens. Then divide the plants into groups with similar watering needs, and plants that are in full sun or in a shaded areas. Next, take into consideration the soil type, and concentration of plants. Use this information to select the water emission devices and to estimate the total flow rate (see the example below Ref: htd1).

Design Layout Example (Ref: htd1)

About the Soil

Soil is like a storage room for plant nutrients. It is the medium through which water and nutrients move. It anchors plants and is a reservoir of water for plant growth. There are various types of soil with different characteristics which determine what types of drippers or micro sprinklers Sandy Loamy Clayshould be used. In sandy soil, where water will tend to go straight down, use closely spaced 2 GPH drippers at 10-12" apart, or micros sprinklers in a wider spacing. In loamy soil, the water will move slowly and will spread evenly, so use 1 GPH drippers with 16-18" spacing. In clay soil, where water will be absorbed very slowly, use .5 GPH or 1 GPH drippers at a wider spacing (18-24" apart) or micro sprinklers and sprayers with adequate spacing.

Determine Soil Types

With a drip system, water is applied slowly to the root zone at a single point. The water is acted upon by the forces of gravity (downwards) and capillary action (outwards), producing a wetting pattern characteristic of the soil type and the water application rate. To determine which type of soil you have in a given area, take a handful of dry soil, grip tightly and release. Sandy (coarse) soil will crumble and fall apart, loam (medium) soil will hold together but then easily break apart, and clay will mold without breaking. For more precise information, consider having a soil test conducted. Many universities offer this service through their extension offices and master gardener programs.

Sketch the Property or Area

Start by making an accurate top view sketch of the areas that need to be watered (see Design Layout Example Ref: htd1 above). Be sure to add details such as the outline of the home, any retaining walls, sidewalks, paved areas, all the plants, and the water source locations accurately and to scale.

This will require measuring the area. We recommend using graph paper with small squares. This will make drawing to scale easier. Each small square on the graph paper could represent one foot of the property; this scale is usually appropriate for residential landscapes. Modifications can be made as needed, such as 1" graph = 10'. ( download our pdf graph )

Various Methods to Start a System

Determining how to start a system, and what products to select, are important decisions that should be made carefully. The correct choice will depend on the size of the area, the availability of water outlets, the garden design/layout, and the type of plant material to be irrigated. Of the following five methods, choose the option(s) that is most feasible and appropriate for your particular use:

The typical home garden may require one or more watering zones. For each situation, DIG provides a convenient and efficient irrigation solution.

Method 1:

Starting from a faucet, above ground installation using 1/2" poly tubing

Method 2:

Above ground installation starting with an anti-siphon valve

Method 3:

Below grade installation using an AC or DC in-line valve

Method 4:

Retrofitting an existing sprinkler system with multi-outlet drip heads

Method 5:

Retrofitting an existing riser with a conversion elbow

Product Classifications and Watering Method

Most residential landscapes are quite diverse and usually consist of up to four basic plant groups or categories as follows:

DIG provides different emission devices specifically designed to effectively and efficiently irrigate each plant group. To choose the correct emission device, please refer to the following guidelines: