A catchment in Starkville consists of an asphalt pavement that drains into a rectangular concrete channel. The asphalt surface (n 0.012) has an average slope of 0.6% and the distance from the catchment boundary to the drain is 165 ft. The concrete drainage canal (n-0.013) is 100 ft long. 0.8 ft wide and 0.7 feet deep and has a slope of 0.8 %. For an effective rainfall (2 yr 24 hour rainfall) of412 in the flow rate in the channel is estimated to be 1.0 cfs. Estimate the time of concentration in the catchment (assume sheet flow in the asphalt).