Question $2$:

The figure overleaf shows a canal as it crosses a low lying river flood plain between two clay embankments. A typical soil profile is $1$m of sand over $10$m of silt, which is underlain by impermeable bedrock. Over dredging of the canal has removed the clay lining from the bottom of the channel. The canal is therefore leaking through its bottom.

$*)$Identify all boundary equipotentials and all boundary flow$-$lines for this flow regime.

$[1$ mark$]$

$($ii$)$ Complete the flownet for this flow regime, and annotate the equipotentials with their total head.

$[3$ marks$]$

$($ili$)$ Calculate the volume of water that will be lost from the canal $($per unit length and time$).$

$[1$ mark$]$