An open drainage canal with a rectangular cross section is $3 \mathrm{~m}$ wide and $1.5 \mathrm{~m}$ deep. If the canal slopes $950 \mathrm{~mm}$ in $1 \mathrm{~km}$ of length, what is the maximum capacity of the canal in $\mathrm{m}^{3} / \mathrm{h}$ ?