QUESTION $3$

$(30$ MARKS$)$

a$)$ Determine the discharge for a common clay drainage tile pipe with thickness of $25mm$ and internal diameter of $233mm,$ running half$-$full of a slope that drops $1m$ over $1100m.$ Use Mannings equation, $n=0\mathrm{.}013.$

$(10$ Marks$)$

b$)$ Design a rectangular channel in formed unfinished concrete which has a discharge of $5\mathrm{.}75\frac{m^3}{s}$ and a slope of $1\mathrm{.}2\%.$ The normal depth is $\frac{1}{2}$ of the width of the channel. Using manning's equation, calculate the width and depth of the channel, $n=0\mathrm{.}017.(10$ Marks$)$

c$)$ An open channel as shown below has a slope of $0\mathrm{.}015\%.$ Calculate discharge at depth of $3ft$ and $6ft.$ Use manning's equation, $n=0\mathrm{.}04.$

$(10$ Marks$)$