def pRunoff(NYrs, DaysMonth, InitSnow_0, Temp, Prec, AntMoist_0, NRur, NUrb, CN, Grow_0, Area, PhosConc, ManuredAreas,
            FirstManureMonth, LastManureMonth, ManPhos, FirstManureMonth2,
            LastManureMonth2):
    result = zeros((NYrs, 12, 10))
    rur_q_runoff = RurQRunoff(NYrs, DaysMonth, InitSnow_0, Temp, Prec, AntMoist_0, NRur, NUrb, CN, Grow_0)
    p_conc = PConc(NRur, NUrb, PhosConc, ManPhos, ManuredAreas, FirstManureMonth, LastManureMonth, FirstManureMonth2,
                   LastManureMonth2)
    for Y in range(NYrs):
        for i in range(12):
            for l in range(NRur):
                # += changed to =
                result[Y][i][l] = 0.1 * p_conc[i][l] * rur_q_runoff[Y][l][i] * Area[l]
    return result