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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def height_water_critical(FlowRate, Width):
 """Return the critical local water depth."""

    #Checking input validity
    ut.check_range([FlowRate, ">0", "Flow rate"], [Width, ">0", "Width"])
    return (FlowRate / (Width * np.sqrt(gravity.magnitude))) ** (2/3)