Please forgive me for my bad English.
I am wondering if somebody could help me with one particular issue that has been puzzling me for some time.
I started reading the NDS Principles of Exterior Drainage publication. On page 55 of that publication they solved the impervious surface drainage of the sidewalk in front of the house and the cement porch behind the house, by simply angling them towards the lawn:
Why is this so? Is this the correct approach in solving the impervious surface drainage of the sidewalk and the porch? Or should both of them have a catch basin in the middle of them?
What confuses me is this principle of simply angling them (the sidewalk and the porch) towards the lawn. Is this a good approach or not?
I would be very grateful for any kind of reply.
I apologize if this question is at the moment not directly related with SWMM. I tried contacting the NDS but never got any kind of reply.
Thank you in advance.