def sdf(L, S, T):
    """
    Calculates Stream Depletion Factor given:
        L - Shortest distance from well to stream (m)
        S - Storage coefficient (-)
        T - Transmissivity (m2/d)
    Returns:
        y - stream depletion factor
    """
    y = L ** 2 * S / T
    print(
        'Stream Depletion Factor (SDF) for L:%.2f, S:%.2f, and T:%.2f = %.2f' %
        (L, S, T, y))
    return y
