“…To account for variability, a normal distribution was applied to flow. An exponential distribution was applied to the amount of rainfall, since rainfall is known to follow this statistical trend (Nikolaidis et al, 1994). The mean and standard deviation of flow (10 analyzed storms) from the copper roof area (42 ± 29 m 3 ), the paved area (2,720 ± 1,900 m 3 ), the grass area (3,500 ± 1,550 m 3 ), the noncopper roof area (1,610 ± 1,200 m 3 ), and the baseflow (1,620 ± 750 m 3 ), all contributed to the 9,320 ± 6,560 m 3 of water observed at the outlet of the watershed during a rainfall event.…”