This elevated urban plaza is surrounded by a $2^{\text{'}}$ wide seating wall. The top of wall elevation is $57\mathrm{.}0$ and the wall height is a consistent ${18}^{\text{'}\text{'}}($a reasonably comfortable seating height$).$ The minimum permissible slope on the plaza is $.01($required for positive surface drainage$)$ and the maximum allowable slope is $\mathrm{.}02.$ Using area drains $($not trench drains$),$ create a successful grading and drainage plan for the plaza showing the necessary divisions of the pavement, the location of each drain, and all required spot elevations and slope arrows. $($Note: if you have repetitive calculations on your plaze you may show typical results for each type$).$