In the system shown, pipe $1$ is $900-mm$ smooth concrete, $1500$ m long; pipe $2$ is $600-mm$ cast iron, $900$ m long; and pipe $3$ is $600-mm$ cast iron, $400$ m long. The elevations of the water surfaces in reservoirs A and $B$ are $75$ and $67$ m $,$ respectively. The water temperature is $15C.$

What elevation of the surface of reservoir $C$ will give a discharge through pipe $1$ of $1\mathrm{.}2\frac{m^3}{s}?$ Neglect minor losses and assume the energy line and hydraulic grade line are coincident.

DO MULTIPLE ITERATIONS