RATIONAL METHOD HOMEWORK PROBLEM # $2$

As the newest water resources engineer at the Cheyenne River Valley Engineering Company, located in Belle Fourche, South Dakota, you have been tasked with determining the peak discharge runoff that will be the basis of the design for a proposed culvert needed for a new road connecting Mud Butte with the town of Zeona, located approximately $20$ miles apart. The drainage basin upstream of the collection point for the culvert has been determined to be $34$ acres in size. The basin has a maximum flow length of $50$ feet, with a total drop in elevation of only $0\mathrm{.}015$ foot, to the natural channel that will deliver water to the culvert collection point. The roughness coefficient for the basin is $0\mathrm{.}090$ and the soil has been determined to have a slow infiltration rate of approximately $0\mathrm{.}15$ inches per hour when wet. The channel itself is $2,250$ feet in length, has a slope of $0\mathrm{.}018f\frac{t}{f}t,$ a hydraulic radius of $1\mathrm{.}62$ and a roughness coefficient of $0\mathrm{.}040.$ Land use for the drainage area is $67\%$ residential $(\frac{1}{2}$ ace lots$)$ and $33\%$ sandy soil pasture mainly used for horses owned by the local residents. The pasture covers the steepest area of the drainage and has a slope of approximately $3\%.$ Using the provided Table and Figure, you are to determine the peak discharge that will occur during a $15-$year design rainfall event using a two$-$year $24-$hour rainfall of $3\mathrm{.}30$ inches. Show your Boss what you can do$!$