An irrigation canal has a rectangular cross section. At one point where the canal is $18\mathrm{.}8$ mm wide and the water is $3\mathrm{.}75$ mm deep, the water flows at $2\mathrm{.}70$ cm$/$scm$/$s $.$ At a second point downstream, but on the same level, the canal is $16\mathrm{.}1$ mm wide, but the water flows at $12\mathrm{.}0$ cm$/$scm$/$s $.$ How deep is the water at this point?