I recently purchased a home with an existing AGP. The previous owner has winterized the pool which included removing the drain cap off of a Dream Line High-Rate Sand Filter. We've recently had some heavy rain and now there is a steady trickle of water coming out of the drain on the sand filter. Over the last several days, the area around the pool has flooded. I am extremely new to pools and do not know if should this be happening? I imagine that the excess rain water is flowing through the overflow and making its way into the sand filter which then drains because the cap is off... I know I'm not supposed to put the drain cap back on, but I also don't want my yard to continue flooding. Thoughts?