Q$3.$ Consider the overflow spillway shown in the figure below. The design spillway discharge is computed as $Q_e-300\frac{m^3}{s}.$ The total crest length of the spillway is $25m.$ There are three squared nosed piers with rounded corners, each $1\mathrm{.}2m$ thick. Headwalls of square abutments are $90$ with the flow direction. Ignoring the headoss over the spillway and over a possible downstream end sill, determine;

a$.$ The design spillway hesd.

b$.$ The required lowering of the river bed for the stilling basin; and

c$.$ The tve and dimensinene of the stilline hasin