Water flows over a broad-crested weir that has a width of \(4 \mathrm{~m}\) and a height of \(P_{w}=1.5 \mathrm{~m}\). The free-surface well upstream of the weir is at a height of \(0.5 \mathrm{~m}\) above the surface of the weir. Determine the flowrate in the channel and the minimum depth of the water above the weir block.