- Drip Irrigation Tutorial -
Design

Drip irrigation is an easy way to water your yard in the most efficient, least labor intensive manner.
With a timer, it can be an automated system that will mostly take care of itself, requiring only a bit of maintenance to keep things running smoothly. But getting to that point may seem to be a somewhat daunting task. In this series of articles, we hope to show you that it doesn't have to be that way and to give you some idea of how to approach the task.

This first article of our drip irrigation tutorial will address some of the things you will want to consider in designing your drip system. The second article will discuss various products and why you might choose one over another. The third article will discuss installation issues and the fourth article will discuss maintenance and troubleshooting.

There are many different scenarios for drip systems; residential landscapes, market gardens, farms, wind breaks, orchards, etc. This series of articles will be geared primarily towards residential landscapes and gardens. Other areas will be covered at a later time. This tutorial will really just scratch the surface, but hopefully it will give you some ideas and help you get started.

A glance through our catalog, or a browse through our web site, will show you that there are many choices you can make to put together a system that works for you and your garden. There is almost always more than one way to achieve a successful system. Sometimes it may seem like there are too many choices, but keep in mind that drip is forgiving and can usually be easily modified if something isn't quite right the first time out. Adding on to a drip irrigation system can be as simple as popping a couple of emitters into an existing line to water a new planting, or may involve splitting one "zone" into two, if more water is required than is available using the existing tubing.

You may want to consider starting with a drip system in just one area of your yard. You can try different types of drip and spray devices to see what you like and what works best for you, then expand the system to meet your needs. Taking this approach, you may still want to consider your overall needs so you get the right timer and filter, but you can start small and learn as you go. The Heart Kit and add-ons (see below), the Yard 'N Garden Kit or the Rose Kit can be good choices for getting started with a small system. We think that you'll find that you are quickly comfortable with the system and that adding on to it is easy.

When designing a drip irrigation system, there are a few basic things that you will want to know. The first is how much water you have available, what is referred to as the water flow. To help you with this calculation we have this simple flow calculator. Just take a container (5 gallons is a good size) and time how long it takes to fill at the faucet where you want to start your drip system. Go to the calculator and plug in the container size and the time it took to fill and you can get the flow in gallons per hour. Make a note of this number for later reference.

The water pressure is also something that is useful to know. If you have high water pressure, say, above 60 PSI, you will probably want a regulator on the system. (We have several pressure gauges that can measure water pressure or you may be able to get one at your local hardware store.) Regulators are inexpensive, in the $7 to $12 range, and can protect your system from having the tubing pop out of your fittings.

Another consideration is the type of soil that you have. If you have a clay soil, water from emitters will tend to move farther than if you have a sandy soil. This may affect the spacing and flow of emitters that you choose for your system. For sandy soil, you might use a higher flow (1 to 4 gph) emitter while in a clay soil you might use a lower flow emitter (1/2 gph to 1 gph)

Take a little time to sketch out the layout of your yard and note where the various plants that you want to water are located. Note ones that might need more or less water. Note areas of ground cover where sprayers might be a good choice. If you have vegetable garden beds, note where they are, since they may have different watering requirements from other areas of the yard. Include dimensions so that you can figure out how much tubing you will want to get to all the areas. If you have lawn areas you can note those, however, drip and low volume sprayers are not generally what you will want for lawns.

The next thing to consider is whether to water your yard all at once or break it up into areas, or "zones". Look at your sketch and try grouping plantings that have similar watering frequency requirements. For example, flowers may want daily short waterings, while trees may do better with less frequent but longer waterings and ground cover may want a morning and evening watering. In that situation, it would not work to have everything on the same line. On the other hand, if you have different types of plants that need different amounts of water but can be watered on the same schedule, you can use higher flow emitters or sprayers on the thirstier plants and lower flow emitters on the thriftier plants to balance the system.

Another consideration in deciding how many zones you need is the amount of water required for all the plants in a zone. We offer mainline poly tubing in 1/2" and 3/4" diameters and branch line tubing in 1/4" (this can go to 1/4" Soaker Dripline, individual emitters or sprayers). Our estimate is that the 1/2" tubing can carry around 240 gallons per hour and the 3/4" tubing can carry 480 gallons per hour. By estimating how many plants you want to water and what size emitter you want to use, you can see your water requirement and check if the tubing will carry that amount of water. If you find that your plants are not getting enough water, you can always increase the amount of time that they are watered to give them more volume. In some ways we're getting ahead of ourselves here, since you will need to make some choices about emitters and sprayers to know how much water you will need.

To get a broad overview of a drip irrigation system, check out the system overview page on our site. In its simplest form, the system starts at a faucet then goes to a timer, filter, regulator, tubing and emitters or sprayers. Of course, you don't need a timer but we strongly recommend that a filter be used on all drip systems to prevent emitter clogging. A regulator is generally recommended, though not always necessary, depending on the water pressure and types of emitters and/or sprayers you are using.

Most drip systems start at a faucet, however, it is also possible to start off from a buried PVC line. This can provide a larger water flow and you may tap into the same line at several points with either 1/2" or 3/4" poly tubing. Generally when this is done, a manifold with one or more electric valves is used to control the watering zones. An electric timer is connected to the valves to control when the zone is turned on or off. This is a higher end system and is not covered in this series of articles, however, we do carry a full line of valves and timers and can help you design a system of this type.

We hope that this drip irrigation tutorial has given you some idea of how to start thinking about your own drip system.