A small reservoir has the following storage elevation relationship.

$\backslash$table$[[$Elevation $(m),55\mathrm{.}0,58\mathrm{.}0,60\mathrm{.}0,61\mathrm{.}0,62\mathrm{.}0,63\mathrm{.}0],[$Storage $({10}^{-3}{m}^3),250,650,1000,1250,1500,1800]]$

A spillway provided with its crest at $60\mathrm{.}00$ m elevation has the discharge relationship $Q=15H^{\frac{3}{2}},$ where $H=$ head of water over the spillway crest. When the reservoir elevation is at $58\mathrm{.}00$ m $,$ a flood as given below enters the reservoir. Route the flood and determine the peak flood and attenuation of the flood peak.

$\backslash$table$[[\backslash$table$[[$Time$],[($h$)]],0,6,12,18,24,30,36,42],[\backslash$table$[[$Inflow$],[(\frac{m^3}{s})$