Example $10\mathrm{.}1$

Scenario

A $50$ m long culvert of entrance type $1$ is needed to move rainwater transported from upstream catchment and convey it under the road embankment. The culvert is laid at a slope of $3,5\%$; Ke is $0\mathrm{.}5.$

Assume the runoff is $4,5\frac{m^3}{s}$ and the headwater depth:diameter ratio is $1.$

Questions

$101\mathrm{.}1$ What size of pipe in mm is need?

Check: Inlet control

Given: $\frac{HW}{D}=1\mathrm{.}0m$;$,q=4\mathrm{.}5\frac{m^3}{s}$

From N$1$ D $=1800mm\frac{O}{?}$

$10\mathrm{.}1\mathrm{.}2$ What is the invert elevation at the inlet, assuming the water elevation at the riet end is $100$ m $?$

$HW={1\mathrm{.}8}^{**}1\mathrm{.}0=1,80m$

$IE=100-1\mathrm{.}8=98,2$

$1\mathrm{.}4\mathrm{.}4$ Is the chosen culvert operating under inlet control or outlet control?

Check: Outlet control

$H{W}_0=H+h_0-$LSo