Gary,

Please explain in more detail what you are seeing. What are the Brass T connected to? What are the ball valves connect to? Are the quick connects to energize the system with water? How are the sprinklers energized with water? Did the previous owners gut the system and leave you with the remnants they couldn't take easily? I would look at how to get water to charge your system up and see what happens. Aloha

Let me start at the beginning.

In the back of the house, beneath the outdoor faucet, there are two flexible black tubes coming out of the ground. I assume these are polyethylene pipes. Each has a six inch, spring wrapped "hose saver" at the end, but neither reaches the faucet. I've tested them using a short garden hose to connect them to the faucet, one at a time - no manifold or Y. I've added a cheap plastic back-flow valve to the faucet.

Walking in the direction of one of those underground pipes, in about 20 feet there's the first of several in-ground round valve boxes. I think they're NDS 6" boxes. In the box, there's a brass T connecting pipes in and out of the box. The base of the T is pointing up, with a brass ball valve (one of those with a straight handle that turns 90 degrees), and male threads at the top. Connected to those threads is an ordinary plastic hose-end quick-connect (female on the quick-connect side, so this has the spring mechanism). The top of the quick connect is just below ground level, so that the box cover fits over it. There are two or three more such boxes in the lawn, at about 15 to 20 foot intervals. Continuing beyond the last box is a perennial garden that has several above-ground spray heads on risers at various heights.

The second in-ground pipe at the faucet feeds the far part of the perennial garden. I don't recall off the top of my head whether there are any valve boxes for this zone. There's similar stuff for the front yard.

Connecting water to one of the pipes below the faucets results in the spray heads at the far end of the run working. I've tested one of the in-ground boxes by connecting a very cheap pop-up spray head with a couple of adapters. With the valve opened at that box opened, the spray head works - as do the remainder of the fixed spray heads at the end of the zone. While this sort of spray head has enough distance to reach the next valve box, it doesn't have nearly enough distance to reach the edge of the lawn in the perpendicular direction, so I need something stronger than a 15' spray head. Using a $3 spray head like this is pretty hokey, but has the advantage of not needing a hose.

Oh, I should add that the previous owner left behind a box of supplies that included several cheap plastic stake-mounted impact sprayers, one metal stake-mounted impact sprayer, one metal impact head (I've no idea of how to mount it), an assortment of cut-off risers and white pvc remnants. There's nothing in the box that I can see would have been used to actually connect water to any of these sprayers. I assume the risers, etc. were used for the fixed sprayers in the perennial garden.

It sounds like whoever installed the system worked for a school district. They used to have impact sprinklers on quick connects like you describe but there should be a valve to isolate the spray heads just like the quick connects have.

Gary,

I agree with Mike a park or school would have a series of quick connect for hoses and portable spray heads to be positioned where they were needed(bald or yellowing areas). It seems to me that you have to start from scratch. Design what you would like. Use as much of the old system as you dare and go from there. Do it one area at a time or if you can hire a landscaper to do it all at once. Make sure to get three contractor quote to ensure the most reasonable local price. Post the info from the quotes here and we can make a critique. Aloha

Thanks for those answers. At least now I know that the people who installed it weren't totally crazy.

After poking around below the shrubbery and ground cover where the line enters the perennial garden, I found the valve. There are stretches where the piping runs above ground, but I suppose that's ok. I also found a loose length of poly, maybe 25 feet long, with an elbow and quick connect at one end and a clamp at the other. I figure it's headed for the trash.

We're not really interested in replacing the system; we've had enough other expenses. Mostly I want to make sure we don't lose the perennials, as well as making it as easy as possible to water the lawn. The lawn is in poor shape anyway, and if it weren't for the leach field, I'd be more interested in getting rid of it. Right now, my idea of cutting a 15' hose into 5' lengths seems to be working without leakage, along with a couple of new impact sprinklers.

So my remaining concerns are just finding a cover for the one box that's missing one (probably online), and figuring out how to drain the system for winter.