$4\mathrm{.}3\mathrm{.}8.$ Three reservoirs are connected to a junction by branching pipes $($Figure P$4\mathrm{.}3\mathrm{.}2).$ An $8,000-$ft$-$long,

$3-$ft$-$diameter pipeline carries $75\mathrm{.}0$ cfs of water from reservoir $1($elevation $3,200$ ft$)$ to junction J$.$ Flow

from the junction travels through a $2,000-$ft$-$long, $2\mathrm{.}5-$ft$-$diameter pipeline to reservoir $3($elevation

$3,130ft).$ Additional flow from the junction travels through a $3,000-$ft$-$long, $2-$ft$-$diameter pipeline to

reservoir $2.$ Determine the water surface elevation of reservoir $2.$ All of the pipes are made of PVC

and have a Hazen$-$Williams coefficient of $150.$

Figure P$4\mathrm{.}3\mathrm{.}2$