why are there two skimmer access holes?

[abfab]

Our house came with an inground pool (13,000 gallons) and we are trying to figure out the skimmer setup.

On the pool deck there are two skimmer access hatches located about 8 feet apart, on the same side of the pool. One is empty... its just a big pipe with some water (presumably rain water) that has accumulated inside. We don't see any pipes connected to it and it does not have any opening in the pool. The other skimmer is the one that we use. It has two holes under the skimmer basket. The one closest to the pool has always been plugged. Since we don't know what its for we've left it that way.

What is the purpose of the empty hole? Is the skimmer hole that is plugged somehow connected to it?

 

[Charlie_R]

Do you know anything about your ground water table height?

It could be the "dry well" dug when the pool was installed to pump the high water table down to a safe level while installation proceeded.

 

[duraleigh]

Is the skimmer hole that is plugged somehow connected to it?

Two holes in a skimmer bottom is common. Unless their is a use for both (connecting to another skimmer, drain, etc.) the other is plugged.

It is not related to your other access hole which I also think is a dry well.

 

[savagesix]

Maybe an autofill that is not being used? Is there a return eye in the pool wall around the area of the mystery hatch?

J.

 

[abfab]

Thank you for your replies. Does the following information provide more clues?...

Behind the empty hole is a flower bed that we just dug up in order to fix our drainage/grading problems. While doing this we found the pool's original backwash pipe. A previous owner had disconnected it, we assume due to the problem of standing water in that corner of the property. Could the empty hole be a dry well to absorb the extra water produced from that pipe?? When we look into the well we don't see any pipes going into it, unless perhaps its below the water somewhere??

In answer to the other questions, there are two returns on that side of the pool (the other two are at the walk-in steps). One is located between the two hatches, closer to the empty one, the other is in the shallow end. I don't know what our water table height is. We are somewhat close to the lake so I would assume that its fairly low.

 

[Charlie_R]

Try this - tie a weight to a long piece of twine, and lower it down the hole. If it stops just below where the bottom of your pool would be, then it most likely would be a dry well put in when they built the pool. Any shorter, and you would need to investigate further about pipes entering or exiting.