$(40$ pts$)$

A dam is to be designed at the flow section in Figure $4.$ Precipitations, inflows, pan evaporations and water usages are given in Table $4.$ Drainage area is $10000k{m}^2,$ pan coefficient is $0\mathrm{.}8,$ spillway crest level is $150$ m $,$ minimum intake level is $125$ m and reservoir level at the beginning of March is $140$ m

Note: Y is the last digit of your student number

Table $4$: Inputs and outputs.

$\backslash$table$[[$Months$,$March,April,May,June$],[$Inflow $(\frac{m^3}{s}),8\mathrm{.}5+Y,4\mathrm{.}3+Y,2\mathrm{.}5+Y,2\mathrm{.}2+Y$

Y$=8$