16.1.21 Rework Example 16.1.6 for a 5-ft curb-opening inlet. 16.1.6 Rework problem 16.1.5 for a 25-year storm. 16.1.5 Determine the peak runoff from 500 ft of pavement (32 ft wide) that drains toward a gutter (for a 10-year frequency storm) in Phoenix, AZ. The pavement slope is 0.005, n = 0.016, and C=0.9.

A catchment area has a time of concentration of 20 minutes, an area of 20 has. and a runoff coefficient of 0.25. Estimate the peak discharge corresponding to a 25-year period if the intensity-duration-frequency for the storm in the area can be expressed by KT* i = D + a where i = intensity in cm/hr. T = return period in years, and D = duration of storm in hours; The coefficients are: K = 6.93, x = 0.189, a = 0.50 and n 0.878

If fo = 0.7 in./hr, fc = 0.2 in./hr, and K = 0.5 hr-1, determine the distribution of losses and the depth of rainfall excess for 2-hour storm with intensity of 1.3 in/hr.

Answer these both questions a. The total observed runoff volume during a 4 hr storm with uniform intensity of 2.8cm/hr is 25.2 x106 m3 from basin of 280km2 area. What is the average infiltration rate for the area. b. A volume of 3x106 m3 of groundwater was pumped out from unconfined aquifer uniformly over an area of 5 km2. The pumping lowered the water table from 102 to 99m. The specific yield of the aquifer is?

8. Determine the mean runoff flow in cfs from a drainage area of 175 acres using the English equation for a 25-yr frequency in inches per hour in Nevada. The area is sloping at 2% and is covered with poor surface grass. The furthest point from the inlet is 72 meters.

Compute the location of the first gutter inlet from the crest, considering the following information:   Maximum allowable flow = 0.35 m3/s Composite runoff coefficient = 0.40 Intensity of rainfall = 125 mm/h Width of drainage area = 75 m

A 6-h storm had 6 cm of rainfall and the resulting runoff was 3.0 cm. If the pindex remains at the same value the runoff due to 12 cm of rainfall in 9 h in the catchment is?

Determine the peak runoff (Nearest whole number) from a 100-year storm for the watershed described below: Field 1: 192 acres, 2% slope, cultivated, sandy soil Field 2: 38 acres, 8% slope, pasture, tight clay soil Field 3: 40 acres, 11% slope, woodland, silt soil The drainage way is 4000 feet with a 0.1% slope.

5.3 Estimate the runoff volume, in mm of depth, from 80 mm of rainfall on a 90-ha watershed during the growing season. Assume antecedent rainfall condition II, 50 ha of row crop contoured with terraces, poor condition, soil group C, and 40 ha of alfalfa, straight, good condition, soil group B. 5.3 Estimate the runoff volume, in mm, m3, and ha·m, for the watershed and conditions in Problem 5.2, except that a 60-mm storm occurred 3 days before the 80-mm rainfall. 5.4 Estimate the runoff volume, in mm, for the watershed and conditions in Problem 5.2, except that no rainfall occurred for 6 days before the 80-mm rainfall. 5.5 Estimate the runoff volume, in mm, for a 24-h, 50-yr return period storm at your location. Assume the watershed conditions in Problem 5.2.

Information on the 50-year storm is given Duration (minutes) 15 30 45 60 180 Rainfall (mm) 40 60 75 100 120   A culvert has to drain 200 ha of land with a maximum length of travel of 1.25 km. The general slope of the catchment is 0.001 and its runoff coefficient is 0.20. Estimate the peak flow by the rational method for designing the culvert for a 50-year flood