That's a tough one that will require much homework, some math and a touch of engineering if you're on a slope. It's worth the trouble. I have yet to do this, but I have tinkered with irrigation from rooftop to tanks to garden which is downhill from the rooftop making things easy for me.

With all those beds, it sounds like a water pressure gauge is in your future. You can attach it directly to the outdoor faucet or at any point at the end of the irrigation at any point to measure water pressure which will vary according to multiple variables like slope, distance, originating psi and the irrigation hoses.

I'm assuming you're drawing from an outdoor water tap attached to your house plumbing. The pipe under your house leading to the outdoor tap is usually 1/2" pvc coming from a bigger 3" pipe. The reduction from 3" to 1/2" in size provides needed friction. Generally, the water at the tap gauges at 50 psi. At least, that's the universal standard for modern homes and some old ones, too.

If you're thinking that less than 50 psi at the water tap requires a bit of plumbing work, you're correct. See. It can get complicated. And if you're thinking that the longer distance from your house tap to the garden beds might require a higher psi than 50, you'd be correct for this, too. They sell gadgets you can put on your tap to create more friction and raise that psi.

The pressure from the irrigation tubes are detailed, too, depending on grade, slope (run,rise), the distance between the tap and the end of the irrigation hose at any interval and how many holds that sucker has and how big those holes are. lol Irrigation hoses come with helpful specifications.

Your absolute best bet is to refer to the dealer from which you buy your irrigation system. OR if you're like me and forced to DIY, there are some serious step-by-step instructions on the internet.

I wish you luck and look forward to the day I can put my knowledge to use with my own.

bon

I hope someone who has a technical way of doing things will answer your question about water pressure because that's beyond my scope of experience. I'm not technically-inclined at all and my eyes glaze over when irrigation guys start taking about water flow and gallons per hour and so forth.

We have very high water pressure at our outside spigot and have to use a pressure regulator to make the flow of water low and slow. In many rural areas, the local water co-op installs the water line with high pressure available since lots of rural folks have either agricultural or animal needs that require higher water pressure out on the land than you would have inside your house, and then you install (or your homebuilder's plumber installs) a pressure reducer before the water enters the house so that the high pressure doesn't destroy things in the house. On the day I came up from Ft. Worth to be here when the water co-op workers installed our water line, they told me over and over again about the need for a pressure reducer to be used when water was piped into the house after it was built. (Clearly they understood that they were dealing with a city girl who didn't even know what a pressure regulator was, but I got their message loud and clear.) If you are in a standard urban or suburban neighborhood, you may not have extemely high pressure like we have out here in the country, but you still likely will need a pressure regulator on your drip irrigation system.

Drip irrigation systems used for residential landscaping and home gardens are low-pressure, low-flow and, in fact, 'slow and gentle' is the way you want them to work, so I cannot imagine that you wouldn't have enough water pressure unless your property is hilly and you're trying to run water uphill and downhill all at the same time (which is possible, by the way, but requires some pressure-compensating components). Hopefully your yard is relatively level as that will make the installation and use of drip irrigation very easy. If your garden beds are raised, they make risers that carry the water up into each raised bed.

Here's what I did with my first drip irrigation project:

I went to Home Depot and bought a kit. I installed it following the directions that came with it. I turned it on. It worked. Period. See how easy that was. It was a different story with the big drip system running off the outside faucet to the veggie garden which is much larger and more complicated, so I was glad my first experience was with a smaller, more simple system that was a lot less complicated and less intimidating. That sort of paved the way for having a larger system later on as the veggie garden got bigger and bigger over the years.

Later on, when we chose to expand the drip irrigation system, I spent hours poring over a catalog and reading it, learning the difference between different types of system components, and then I just ordered a kit and some extra parts and we put them together and made it work. Luckily Tim is very good at technical stuff like this because I'm not. Installing a drip irrigation system actually sounds harder than it is, and you can keep it very simple, or you can install a lot of cut-off valves, for example, that give you the option of watering different beds at different times (instead of watering everything at the same time in the same way) which takes more time, but gives you a lot more versatility since not all plants have the same water needs. You can install timers that turn the system on and off, which is very handy for when a person goes on vacation. The sky is the limit as you can design a system that suits you.

Many drip irrigation supply stores (DripWorks is an example of one) will design your drip irrigation system for you if you provide them with a layout of your garden. Many have online programs you can use at their websites to design your own system. You can buy off-the-shelf basic kits at places like Lowe's or Home Depot. There's many different ways to do it. You can make it really simple or really complicated depending on how much you like to fiddle around with technical stuff. I like keeping it as simple as possible.

Most of the men I know speak a whole different language when talking about irrigation systems like this and most of what they say flows in one of my ears and out the other ear and I have no idea what they are talking about. I have a brother-in-law and nephew who install irrigation systems in Texas and their technical know-how just boggles my simple mind. I just want to be able to turn on the water system and have water flow out into the garden and I don't get into all the technical details. I don't even want to know the technical details. In our family, that sort of stuff is Tim's job. Don't get me wrong. I greatly admire people who have scientific and technically-oriented minds and can do all the math and figure out different configurations and water flow for different situations and such, but my brain just doesn't work that way.

At this link, you can download the Drip Works drip irrigation planner.

Dripworks Free Drip Planning Guide

If you click on this link, you can see the Drip Works garden planner. It is pretty cool and you can use it free for a week. Once you've planned your garden, you then can plan your drip irrigation system.

Drip Works Garden Planner

Also on their website there's lots of other info available, including a blog. I read everything I could get my hands on back when I was trying to figure out how to get started with drip irrigation. Most drip irrigation companies have all kinds of info, usually including blogs and how-to videos, on their websites.

A water pressure test gauge will tell you pressure at the faucet.

http://www.homedepot.com/p/3-4-in-Plastic-Water-Pressure-Test-Gauge-DP-IWTG/100175467

Keep in mind, most drip systems are designed to operate at lower than normal household water pressure. Many operate at around 25-30 lbs.

In the unlikely event you find you have an inadequate supply of water, simply set up zones. Timers and control valves are relatively easy to install and program.

Now see there---I knew okoutdoorsman would have the right technical answer! What a handy little gadget that water pressure test gauge surely must me. That's the kind of thing that I never know about, but then, I already knew we had extremely high pressure from our water spigot before we started, so it was more an issue of what do we do to reduce it.

I am not the only one that gave a right answer! I see a lot of good info in the above posts. Like many, I've had to learn the hard way.

Some of the lessons learned have been, don't just design your system based strictly on this year. If a person is dealing solely with raised beds, it may not matter as much. Other than rotating crops, the bed's should be static, eliminating the need to move the manifold. Feeder lines would be the only thing that I would try to keep mobile.

Another mistake I made was not buying the specialized fittings that are designed for use with 1/2" and 1/4" poly. I still have buckets of the gray barbed fittings leftover. They are cheap, so I thought I was saving money! By the time I purchased clamps and crimp bands I was spending 2 to 3 times the cost of the snap fittings most of the common systems use!

Drip irrigation can be as simple or as scientific as a person choses. I like simple! If you find yours doesn't deliver the desired amount of water in an hour, set it to run two hours.

Great post. I stand corrected. Ya'll saved me future hassles.

I am really glad I live in a part of the State that gets a lot of rainfall and that I have a faucet at the edge of my garden. I manage. LOL

Drip irrigation is GREAT. I bought 2,000 feet of it a few years ago. If my potatoes get thirsty, I find it very easy to lay out the drip line and hook it up.

However, it gets very interesting at the plots where I don't have water under pressure. Gravity feed will not work with my drip line. I may have to buy or build a pump.

Johnny

Thank you everyone for your thoughtful replies! I live on flat land and I have 15 raised beds of various sizes. It takes up about 3/4 of my 65 feet long and 55 feet wide yard. And this includes walk ways. The area sounds large, but it is not really. Most of the beds are 4x4, with only 2 3x12. I have a couple of wee tiny beds but they are not going to be included. There is a space under some trees that may be included, but not this year. I can see getting water up in the raised beds are going to be the challenge. As well as calculating how much I will need in footage of hose. I definitely will buy a pressure gauge for the facet! I have purchased a kit that is expandable to start with so if I have to do some of the beds but not all at this time I can.

And here I thought this was going to be easy....LOL....

I'd love to do this, but I may have to print this thread and spend some time at the store looking. And I totally Pinned the above provided links! You guys are phenomenal.