Agreed. Was trying to give a quick answer to the question about "slope". My point being that individual developments have gotten better about not contributing to the issue of adding to offsite flooding. Still could be improved but there are larger concerns. Some we can control and some we cannot.
It is interesting how water rules the world to a large extent. Some, such as us, often have too much while others have too little. Out West there have been discussions on the legality of rain collection systems on private property. The argument being that they are capturing a "public" water source for private usage.
Many don't understand the political power of water around the world either. In many countries those that control the water have the power. Especially if we are talking clean drinking water. Water is one of the biggest weapons utilized in third world countries.