This area with no grass has a sprinkler head which tends to drain off water due to head loss, but the last time I watered was on Friday. The area is still moist compared to the soil in other areas around the house. This area doesn't get much sun, so could the soil still be holding moisture that well?

If not, I'm concerned about a shower drain leak under the slab. My master shower drain is on the other side of that brick wall. Visual inspection of the drain looks good down to the p trap which is holding water. Would there be any specific symptoms I would notice for a drain leak under the slab?

I'd be more concerned about a pan leak. have you checked it while the shower was running?

You could get a drain plug and see if the water stays in the pan

Also, is that efflorescence?

This shower has a mudset floor with tile, so there's no pan I would say. That is efflorescence that happened about a year ago when we first moved in, but it has pretty much stopped since the summer. The efflorescence happened around the entire house consistently, so it doesn't seem tied to this shower location only.

check the other sprinkler heads off that valve. is it wet around those?

If yes, you probably have a small leak in a sprinkler valve. Seemed like when I lived in Houston and the system was ~9-years old, every spring I'd have at least one valve start leaking and I've have to install a repair kit with new seals. Also seemed to leak out the lowest point in the system so not all the soil around all the sprinklers off that leaking valve was wet.

The soil around the other sprinkler heads on that zone is not wet. The one in my pic is the lowest sprinkler head in that zone, and I've seen it drain water when it's done running. I'm hoping that's all it is, but the last time I watered was 5 days ago. Would the soil really hold moisture that long? It has been pretty humid this whole week.

Thunderstruck xx said:

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This shower has a mudset floor with tile, so there's no pan I would say. That is efflorescence that happened about a year ago when we first moved in, but it has pretty much stopped since the summer. The efflorescence happened around the entire house consistently, so it doesn't seem tied to this shower location only.

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there' still a pan, it's just not prefab.. it's made with a liner.
like this;


Get a drain plug (a balloon can work), plug it, fill it, and wait a few hours to see if water dropped.
It's a fool proof way to see if you can rule it out.

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I've seen it drain water when it's done running. I'm hoping that's all it is, but the last time I watered was 5 days ago. Would the soil really hold moisture that long?

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Yes, especially with clay backed sod.

Could be fiberglass as well

Apache knows better than I do but could also just be a leaking irrigation valve in that zone. Leaking valve will allow a small amount of water to pool around last /lowest head. Cure is to swap out internal diaphragm and guts from a new valve or get a valve rebuild kit.

Check your water meter, make sure everything is off for a few hours, or overnight. If meter does not move you can rule out slab leak.

Yes. That's where I'd start. If it isn't that, based on the location of the shower, my first inclination would be a leakey shower pan.

But it's probably a leaking sprinkler.

I'd add, if it were the pan, I'd expect some wetter or stained concrete where the water would be exiting under the plate.

We're talking about drains, not the water source. All my water lines run through the attic and walls.

Who?mikejones! said:

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Yes. That's where I'd start. If it isn't that, based on the location of the shower, my first inclination would be a leakey shower pan.

But it's probably a leaking sprinkler.

I'd add, if it were the pan, I'd expect some wetter or stained concrete where the water would be exiting under the plate.

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I should add that my actual shower floor is five feet up from the ground level due to the slope of my property, and I don't see any water coming out near the brick at the floor level. Actually, I think I'd see water coming out near the weep holes due to the air gap between the wall and brick.

Check to see if your sprayer head is leaking. If you are using Hunter spray heads, replace it with a spray head that has a check valve, which is only maybe a dollar more than a regular spray head.

I have replaced some of my spray heads with spray heads with check valves to eliminated the puddles around it.

A check valve holds back water where elevation changes occur, preventing wasteful low-head drainage and keeping pipes primed for the next irrigation cycle..

Noted.

On the sprinkler side of things, could there be an active leak even though my sprinkler system is off at the controller?

On the sprinkler side of things, could there be an active leak even though my sprinkler system is off at the controller?

Yes, the controller simply opens and closes the irrigation valve solenoid on a schedule. There is pressurized water in the lines upstream of the zone valve and none in the distribution lines until the valve opens.

A leaking diaphragm allows water to seep from the supply lines out to the distribution lines and eventually the spray head.

You should have a main water supply cut off valve or back flow preventer that you can close upstream of the zone valve box.

Ok, turned off that main valve. I'll see if it dries up over the next week or so while we continue to use the shower. Of course now we're getting rain chances through the weekend.

We had a slow leak in the valve to 1 zone. It only leaked out of the lowest furthest head. Replacing the valve fixed the problem.

For this type of leak, should I see water coming out the top of the head? Because I don't see that.

Thunderstruck xx said:

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For this type of leak, should I see water coming out the top of the head? Because I don't see that.

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I didn't see water come out of the head. Just a wet spot so it was leaking so slow it wasn't visible.