I bought a home last year with an in ground pool that has an overflow drain. The drain, a 2" pipe with a grate in front on the side of the pool, ties to another drainage line that leads to an exit grate in the yard. This other drainage line drains my deck and roof gutters. The problem is during heavy rainfall - water pours into the pool from the overflow drain.
The water flowing in is clean and isn't making it hard to keep the water balanced. I like the "free" water, but this is not how it's designed to work. During a prolonged heavy rain, the pool will overflow onto the deck. Once the rainfall rate drops, the water flow reverses and begins to drain out of the pool through the overflow.
I've been troubleshooting and have come to the conclusion that 1) the piping at the end of the drain run in the yard is too narrow for the amount of drainage flow and 2) there's not enough elevation drop between the entry and exit points. What can't drain fast enough backflows into the pool. I could increase the diameter of the main drainage line but since it runs through a large expanse of concrete, this would be very costly. My lot is relatively flat, so I can't change the elevation difference either.
I did some research and it seems that the best way to prevent this is to add a 2" ball valve to the pool overflow line. Whenever I want the pool to drain, I can turn the valve on after heavy rainfall.
Before going down that path, I thought I'd ask all of you for your opinions. Thanks.
The water flowing in is clean and isn't making it hard to keep the water balanced. I like the "free" water, but this is not how it's designed to work. During a prolonged heavy rain, the pool will overflow onto the deck. Once the rainfall rate drops, the water flow reverses and begins to drain out of the pool through the overflow.
I've been troubleshooting and have come to the conclusion that 1) the piping at the end of the drain run in the yard is too narrow for the amount of drainage flow and 2) there's not enough elevation drop between the entry and exit points. What can't drain fast enough backflows into the pool. I could increase the diameter of the main drainage line but since it runs through a large expanse of concrete, this would be very costly. My lot is relatively flat, so I can't change the elevation difference either.
I did some research and it seems that the best way to prevent this is to add a 2" ball valve to the pool overflow line. Whenever I want the pool to drain, I can turn the valve on after heavy rainfall.
Before going down that path, I thought I'd ask all of you for your opinions. Thanks.
