We are reclaiming a flower bed and extending our existing patio. After a gully washer I am now concerned about drainage for this 5ft by 36ft impervious surface we are adding. We are also adding a stair case in the middle to access the upper yard over a brick retaining wall. The stair case will be 2 risers and end where the retaining wall brick drops off 4 feet wide stairs. For relation each existing concrete square is 2ft by 2ft
So my question is how would you drain? Can I run pvc pipe under the stair case to allow draining under the stairs? Should I drin towards retaining wall and away from house and existing patio? Should I drain towards existing patio and add a channel? The next problem is what to do with the water once it gets to the end of the patio? Just add a French drain along the length of new concrete and funnel to flower bed? Any help would be great. Mainly wondering about the possibility of running pvc under stair case to allow drainage and not ruin concrete integrity. Thanks in advance.