A 200 m × 200 m square parking lot slopes toward one of its edges. The parking lot drains...

A 200 m × 200 m square parking lot slopes toward one of its edges. The parking lot drains into a gutter along the downstream edge. Adjacent land drains away from the parking lot, such that the parking lot represents the entire watershed being considered. The gutter drains into a storm sewer inlet at its center. The longest flow path (corner to inlet) consists of 200 m of overland flow across the parking lot and 100 m of gutter. Velocities are 10 m/minute for overland and 20 m/minute for gutter flow. A cumulative rainfall depth versus duration relationship for a 25-year recurrence interval is provided in the table. C is 0.95.

Use the rational method to estimate the 25-year recurrence interval peak inflow to the storm sewer inlet.