$6\mathrm{.}3\mathrm{.}5$ For the channel and river shown in Figure $6\mathrm{.}3\mathrm{.}4,$ determine the volume of water that flows from the channel into the river. The water surface elevations in the channel and river with respect to the underlying bedrock are $15m$ and $11\mathrm{.}5m,$ respectively. The hydraulic conductivity of formation A is $5\mathrm{.}6\frac{m}{?}$ day and that of formation B is $12\mathrm{.}3\frac{m}{?}$ day.