What's this?

Found this just outside the pool cage. White thing is a float and if you push it down water flows in. Thanks in advance



Pool auto filler. Keeps the pool topped off.

Didn’t that question answer itself?

Thanks James. That did cross my mind but had doubts.

It may be used as to drain all water when it comes in monsoon season. I think there may be large water consist place so this is the facility to drain water.