Rain falls on a 0.05 mi² urban catchment with an intensity of 0.85 in/hr. for a duration of 3 hrs. The soil is classified as SCS hydrologic group C in the entire catchment. Land use within the catchment is as follows: 1) 20% area is business district 2) 40% area is residential district 3) 20% area is forest 4) 20% area is cropland Determine the total runoff volume in ft³.

6. Runoff from a 200 mile² catchment drains into a reservoir than has an average surface area of 4000 acres. The reservoir is to be used for municipal water supply. Annual rainfall over the watershed is 40 inches and the annual runoff is 2 inches. Evaporation from the reservoir averages 40 inches per year. If the surface area of the reservoir is roughly constant with depth, how much will the reservoir depth change in one year?

Solve the problem using the NRCS method for a watershed located right outside New York City, New York for a 50 year storm event. Assume the soil hydrologic group B (65%), C (25%) and D (10%). Given Am-1.29 sm. Impervious = 6.6 acres, Woods =819 acres. Overland flow: L=100 ft, s=4%, fair; Shallow Concentrated Flow: unpaved L= 2300 ft, s=2.7%, stream flow L=9000 ft, s= 3.4% The Time of Concentration is 20¹ 12¹ n = 0.035

Please answer question 2