>> I dont see anything along the baseboards anywhere
I would start by finding the hose spigot outside, then figure out "where it comes out of" inside.
Is there a basement or crawl space? If that doesn't help, try to find any water pipe at all, like sink, tub or washing machine. That may lead you to the main indoor water pipes, which you can then follow and at least find out where they appear from and disappear to.
(I learned that it is good to know where your SHUT-OFF valve is. If you ever have a pipe burst, or need plumbing done, you need to be able to turn off all the water going into your house. The prior owners and/or real estate agent OWE you that info, and I would assume that any place with a building code specifies shut-off valves for any habitation.)
(To get anything out of a real estate agent, you might need leverage. "This house is uninhabitable and fails to meet code without a shut-off valve so WHERE IS IT?" might be the leverage needed to get them to bestir themselves. A real estate agent HAS TO know licensed inspectors who know about building codes for residences. In NJ, we ALWAYS had places inspected before making an offer, and several times were saved from buying lemons, even manufactured-home lemons. Such an inspector could probably find both the shut-off valve and the controls for the presumed irrigation system.)
Bummer that the previous owners didn't leave any information! I would think, especially in Texas, that an irrigation system would be a big "value-added" plus.
Unless they installed a cheap one that promptly broke, or they did not drain it and it froze up one winter and all the tubes ruptured.
If you can find any info, especially where the drain valve(s) are, and how to turn it on, and how to open or close "zone" valves, you might have a valuable item already installed.
I don't know if the "New Jersey threat" would be appropriate to apply to this real estate agent. When the prior owners (and their real estate agent) fail to "disclose" something that lowers the value of the property, like "the irrigation system is broken", they are liable for the lost value and might have to let you renege on the sale. (Just a threat, not something you would DO).
But how liable could they be if something is broken, that they never even claimed to have installed?
Umm, is city water expensive there? It might work fine, but be too expensive to use.
(P.S. One other, remote, possibility is that the old septic system failed and there was no room for an in-code leach field. Maybe they had to replace it with a "Rube Goldberg / chemical engineering" kind of septic system. THAT might need that kind of 4-tube drainage system with six outlets. If they failed to disclose that your septic system is the kind that needs frequent maintenance, they REALLY failed to disclose something!)
