You're going to hit pipe. You will. Accept it, make peace with it, learn how to repair it, and move forward. A lot of people are terrified of their irrigation systems because they don't understand one simple fact: water is not moving through those pipes until the controller opens the valve for that zone. Worst case scenario, you shut that zone off until you fix the leak (or have a pro fix it). If you get super unlucky and hit the main line from the house to the valve boxes (this is the only line that is always charged) your system should have a main shutoff valve right at the house (may be on the backflow preventer). Since you have nothing going on besides lawn and a couple trees, you will need to move heads as you put in beds. The lawn heads will need to be moved to the edge, and you may decide to add irrigation zones for the beds as well. So no matter what, you're going to want to either develop a relationship with an irrigation contractor or start learning about irrigation. If you do any of it yourself, just remember the irrigator's prayer. "Lord, I know you wanted water to flow downhill. Please look the other way before I flip this switch. Amen."

docbuttons, Vegetables have different watering needs that's also dependent on your climate and the time of year. The fine folks here would have to know a little more about what you're growing and where you're located. Here in the desert S/W I have all my gardens setup with drip systems and timers and water every other day, (sometimes more). I also have a fertilizer injection system that fertilizes when I water. Here's a few photos: One of my garden areas with drip hoses in the rows... The fertilizer injection system... I hope this gets you pointed in the right direction for your needs. Greg Nevada

lehua, Thanks for your reply - much appreciated. I suppose I should have checked more into the forum archives prior to posting - would have prompted me to first check into my hydraulic specs. Our water does come from a municipal source, which obtains it's supply from local fresh water natural lakes/ponds and reservoirs. It is treated with chlorine and fluoride (1.0 mg/l) and has a moderate hardness of 68 to 84 mg/l. I just did a test by filling a 5 gal bucket from the freeze-proof garden bibb, timed it with my phones' stopwatch - and it took exactly 60 seconds to fill to the brim, which equates to 300 gal/hr. The main vegetable planting area consists of (6) 36"+ wide x 18 ft long beds, each naturally bermed about 6" above the 18" wide pathways - which are freshly covered in straw mulch each season. Each row slopes along its length, approx 6" in 18 ft., or 2.8%. We also have a couple of 42" x 12 ft wood-plank raised beds for strawberries, herbs and smaller rotating crops. An 8' x 5' onion patch, 10' x 4' raspberry patch and a 40' x 3' mixed use bed along the east garden fence - all with about a 1.5% slope. The soil composition is 12" to 18" of very rich humus, with a mix of loam + grey clay in the subsoil layers. I have been layering at least 3" of my own organic compost over each bed twice/season, which I first break down with my shredder/chipper. Water plumes have always spread very well when hose/pail watering in the past. Organic additives, such as bone meal, wood ash, and dried blood are added regularly, with limestone tilled in the Fall, if soil ph tests require it. Concentrated fish emulsion is mixed with water and applied by hand to each plant during the growing season. Due to some early blight occurring on our tomatoe and pepper plants, which was spread I believe from water ground splash, I'm thinking drip irrigation may minimize this from happening. I have not yet purchased the inline filter, 3/4" mains and 1/2" laterals, but have received the 3/4" ball valves and electronic water timer/valve I had ordered. The author of a Utah Co-op Extension article on the prototype PVC system (see link), recommends drilling 1/16" holes, in 2-3 hole clusters, spaced to align with individual plants. My plan was to dedicate each lateral to plants with similar needs, with all lateral and major pipe joints being separable to accommodate seasonal rotation and off-season storage. Since I have no experience with this yet, I was waiting for the time when my indoor grown seedlings are about ready for transplanting, before determining hole spacing. Drilling should be easy enough to do when that time comes by setting up a jig. Sorry for being long-winded - many thanks for your encouragement, and system endorsement . . . I feel less like a pioneer now. Best, Steve Here is a link that might be useful: PDF - Designing a Baasic PVC Home Garden Drip Irrigation System

lw, Flow is additive so 20 lateral would require a 80 to 100 gpm single source if you use one zone. One usually requires a 20% added insurance flow to make sure you have adequate flow. That is 100 to 120 gpm. If you had two zones you would need 50 to 60 gpm and so on. You can research a 3/4" pipe flow at 20 psi on-line. The flow rate should be around 7 to 12 gpm so you are good there. If your system was using an undersized pipe size, your system would have very high water velocity with water hammer and noise. Your 2" pipe is should be okay at 20 psi but it might be close. You could use a higher pressure for the mainline and reduce the pressure at each lateral. In line pressure regulators are not expensive for 3/4" pipe. You could run the mainline at 40 psi and reduce to 20 psi at the laterals. So a centrifugal pump with 40 psi head with a flow rate of 140 gpm would be adequate or any flow rate lower is you go to more zones. Now it is just a cost isssue. GL JMHO Aloha.