Water table question

[skinpath]

I'm starting to work on a plan to close my pool.

Some of the posts I read talk about taking into consideration the level of the water table when lowering the pool water level for closing.

My question is - how do I figure out the level of my water table and what is "too high"?

I don't have a well and there is no separate hole near the pool that some posts have mentioned.

I do have a passive sump pump drain in the basement which has some water in it. Just eyeballing the level of that water would put it at or below the level of the main drain in the deep end of the pool (about 8.5 feet deep relative to the top of the liner). Obviously this would not be too high, but I just don't know if this is a good indication of the water table.

 

[Catanzaro]

I'm starting to work on a plan to close my pool.

Some of the posts I read talk about taking into consideration the level of the water table when lowering the pool water level for closing.

My question is - how do I figure out the level of my water table and what is "too high"?

I don't have a well and there is no separate hole near the pool that some posts have mentioned.

I do have a passive sump pump drain in the basement which has some water in it. Just eyeballing the level of that water would put it at or below the level of the main drain in the deep end of the pool (about 8.5 feet deep relative to the top of the liner). Obviously this would not be too high, but I just don't know if this is a good indication of the water table.

I would contact the township to determine if you have high water tables. Ask some neighbors as well. This is not my specialty. Although I will tell you that lowering your water 2" below the skimmer should not do any harm. You can easily close your return jets with the black rubber plugs under water. IMHO, leaving water in the pool also insulates its surroundings. My water is below the skimmer (1") and I was able to clear out the main drain almost 100% (vacuum and blowing out lines). My solid tarp usually fills up with a lot of water before the first true cold spell and only a few inches at most freeze on the surface.

What is the frost line in NY? Some parts of NY become real cold right after the summer. Thanks!

 

[skinpath]

It's hard to find a definitive answer on the frost line, since upstate New York varies so much, but it looks like in my area the frost line is in the 36-48 inch range.

Frankly, that sounds pretty deep - should I expect my water to freeze 3-4 feet from the surface of the water, or will the ground surrounding the pool provide some heat transfer and it will only freeze 3-4 feet from the surface of the pool?

 

[Catanzaro]

I feel the ground surrounding will provide some heat transfer. I know the surface water under cover will not freeze about 1" from the liner. There must be too much heat coming from the pool walls.