AGET $220$

Open Channel and Erosion Control Structures Design Homework

$1.$ A triangular shaped channel with a slope of $\backslash (3\backslash \%\backslash )$ is to be lined with a grass mixture. The channel has $\backslash (2$: $1\backslash )$ side slopes and the flow depth will be $3$ feet. If the soils are erosion resistant, what will be the flow rate in this channel?

$2.$ A trapezoidal channel has a flow rate of $45$ cfs $.$ The side slopes of the channel are $\backslash (4$: $1\backslash ),$ the bottom width is $8$ feet, the roughness coefficient for the channel lining is $0\mathrm{.}032,$ and the depth of flow is $1\mathrm{.}5$ feet. What is the approximate slope of the channel?

$3.$ If a channel just like the one in the previous question is to be designed except it will be lined with Kentucky Bluegrass on easily eroded soils, what would be the maximum allowable slope?

$4.$ The runoff into a gully is estimated to be $35$ cfs $.$ To stop the growth of the gully, a boxinlet drop spillway is to be installed that is $8$ feet wide. If the desired depth of flow is $1$ foot, what is the breadth $($B$)$ required?

$5.$ The depth of flow in a trapezoidal waterway is $2$ feet. The bottom width is $2$ feet, the side slopes are $\backslash (1$: $1\backslash ),$ and the channel slope is $\backslash (6\backslash \%\backslash ).$ If the channel will be lined in gravel and the flow rate cannot exceed $20$ cfs $,$ will this design work? Show calculations to back up your answer.