Home Improvement → [Landscaping] Unused Sprinkler System

I'd like to know how to locate sprinkler heads in a sprinkler system that hasn't been used in years and they've fallen under the soil.

I'd like to breathe new life into this system not to water the whole lawn but to water our tomatoes and the shrubs (I planted a hydrangea that is water hungry) and I'd like to have automatic watering as we travel.

It just needs minor repair (an elbow needs replacing where it comes out of the house, a couple of new heads, and a new timer). I may use drip irrigation.

I have no maps of the system. I'd probably use only one zone as we'd be watering just the shrubs and the tomatoes (drip irrigation). I'd probably dig up the rest of the sprinklers on that zone and plug them off. Some of the heads are damaged anyways.

Do the minor repairs to get the water flowing and turn it on (each zone, one at a time) and get those little flags at Lowes/Depot to mark everything. I had to do that here because my system was inoperable when I bought my house.

I powered up the system today, I did so by shoving a garden hose into the riser pipe (had to be cut because the elbow where the PVC meets the copper inside pipe cracked) and I got good enough pressure to get a good amount of the sprinklers to pop out. I got two in the backyard, all three in the front yard and so forth. I think I'll have this thing going with minimal effort. There is three zones. I'm only using two, the third goes into an abutting yard that was part of the property before my duplex was sold. The landlord was hinting at wanting me to water as there was a huge dead spot in the backyard under the tree and she was going to reseed it but was only going to do it if we could water it so fixing the irrigation system is the solution. I already replaced two heads as only was leaking and one was decapitated by a lawn mower.

I just need to redo the PVC joint at the house, replace a couple of broken heads, and get a new timer (old one is locked and I don't have the keys and newer ones use water smarter such as rain shutoff).

I'd also suggest to the landlord if she mentions it having a secondary meter installed so she ain't getting billed sewer but with a property this small the difference won't be big.

I'm fixing this system mainly to water shrubs and the gardens but to water the newly seeded backyard like the landlord suggested.