I have an outdoor drain on a cement apron around our swimming pool. The drain is connected to a length of PVC pipe that runs underground for drainage. During moderate to heavy rains the ground becomes saturated and the drain backs up. I need to access a diagram or plans for a french Drain type system, dos & donts, etc. I was thinking about digging a deep pit, filling it with gravel for the drain. Any info you can provide would be appreciated!! Are there any plans on the internet? Thanks & have a nice day….