Gardening : Starting a Drip Irrigation System : Water Saver: Installation of a kit is simpler than that of a sprinkler system. The benefit is that up to 70% of water can be saved.

If figures are to be believed, the most significant new way to save water in the garden is to install drip irrigation in place of sprinklers. The University of California and others estimate that you can save as much as 70% of the water you are now using.

You cannot water lawns with drip irrigation (although it has been done--more about that another time), but you can irrigate everything else in the garden with drip, from plants in containers on the patio, to citrus groves.

The various drip, trickle, soak and spray irrigation systems seem complicated from a distance. Catalogues of all the various parts only make things more confusing. Pick one up at a nursery and you’ll see what I mean. The vocabulary is baffling. What is a torturous path or an emitter, and what do all those parts do?

And some of the basic concepts--such as how you figure out when to water and for how long--can be confusing.

However, these systems are really very easy to install and use. A lot of work and engineering has seen to that. Those who have installed sprinklers, will find that the parts cost less and are easier to assemble.

But, you’ll never know this until you give it a try. So how do you get started?

Perhaps the best way is to get just your feet wet by beginning with a kit. Most manufacturers offer kits and they can be found at hardware stores, home centers and discount stores.

The kits contain all the parts and although the kit may not be large enough for your eventual needs, by the time you put it all together, and after a few months of using it, you will know how it all works and be ready for bigger projects.

Just having all the pieces in front of you makes them much more tangible and therefore understandable. And instructions are always included.

Fall is the ideal time to give a drip-type system a try because they are the perfect way to get new plants started and should you goof, plants are not likely to die overnight, like they might in spring or summer, for lack of water.

Installing a drip irrigation kit is a bit like building something from Tinkertoys. There’s no real hard work--no trenches to dig, no serious cutting, no threading.

There are a few things to consider before buying the kit however--things you may want to jot down on a piece of paper and take along to the store. With any luck they’ll save you the trouble of going back for additional supplies.

First, have some idea of the square footage you would like to irrigate (measure length and multiply by width). All kits give some idea of how large an area they cover.

Or they tell you how many plants they can water (for instance: two trees plus three shrubs), so also have that information on your piece of paper.

Since most systems are designed to be connected directly to a hose bib or faucet, figure out how far away from the faucet the area you want to irrigate is. You may need to buy some pipe to run from the faucet to the area to be irrigated. You could temporarily use a garden hose if there is a pressure regulator attached at the faucet end so you don’t burst the hose.

Just about everything else you need to know comes with the instructions, so make sure they’re in the box when you buy it.

Finally, make sure you have these essential gizmos: a back-flow preventer, filter and pressure regulator.

Most kits can simply be hooked up to a hose bib or faucet with a Y-shaped diverter that still leaves you with a place to attach the garden hose.

A whole bunch of gizmos are attached to the faucet or Y-diverter, and these are worth learning about right away, because they are part of any drip-type system, or should be.

Most kits comes with them, although they may be barely adequate for the job on low-cost systems. If they don’t, you will want to get these pieces separately. One is even required by law.

Eventually, you will probably want to assemble your own system from individually purchased parts and connect it permanently to a water supply, for a neater, more durable installation, but don’t worry too much about that yet.

Beginning at the faucet or Y-diverter, here are the gizmos in order of appearance:

Check valve. This little device prevents water from being sucked back into the home’s plumbing, water that might contains pollutants, even pesticides. The check valve is required by law.

Sprinklers also use similar devices, but they are called anti-siphon valves. You can use these in permanent installations of drip systems, or the much heftier back-flow preventers that will handle all the tubing and devices you can attach.

Filter. Because all drip-type systems emit water through very small openings, they are easily clogged, so filters are required. Most kits come with very simple filters, usually some kind of tube with screening inside. They will work for awhile, but the first thing you are going to want to replace is that little filter, with something bigger and easier to clean.

Y-type filters are the best (T-types a close second). With these, water is diverted into a side chamber where a large filter screen is located. But, the real plus is the clean-out plug at the end of this chamber.

Open it and you can flush all those particles out of the filter without disassembling it. On some you can even attach a hose so this water is not wasted but directed to plants. Filter screens have different size meshes; 120 or 150 mesh is considered enough for city water supplies.

Pressure regulator. Drip-type systems all operate on very low water pressure. The pressure regulator lowers the home or garden pressure to whatever is optimum for the kind of system you are using. Otherwise some of the parts would burst. Buying the right regulator is a little tricky (it requires some math) so it’s a good thing they’re included in most kits.

The last gizmo is the connection to the system of tubes. In most cases, this is threaded on one end with a compression fitting on the other. Most systems use compression fittings.

Because they operate only on low water pressure, all you have to do it push and twist the tubing into the fitting--no glue, no threads, very easy. If you have trouble making the connection, try dipping the end of the tubing into a bowl of ice water, which shrinks it temporarily.

Pictured is a typical installation designed to water new plants. It is an “in-line” drip system sold by the Natural Gardening Co. (217 San Anselmo Ave., San Anselmo, Calif. 94960), one designed from especially heavy-duty parts by drip expert Robert Kourik, but more about the various kinds of systems in the next installment.