nt conditions. Table 1. Typical Runoff Coeffiicient Surface Type Runoff Coefficient I Surface Type Runoff Coefficient Pavement. Asphalt 0.95 Turf, Flat (0- 1% slope) 0.25 Pavement, Concrete 0.95 Turf, Average (1 - 3% slope) 0.35 Pavement, Brick 0.85 Turf, Hilly (3 - 10% slope) 0.40 Pavement