I have a one grid layer steady state modflow model in gms 10 . When I put one particle at a distance of 100 meters away from the intake well, it entered the well in 70 days with default porosity value of 0.3. Material K value is 0.002 m/s. Then I changed the porosity value to value 0.01 and after running modflow again, GMS informs that particle enters the well in two and a half days. I"m "confused", when there is less amount of effective pores available for ground water to move then GMS tells that water moves faster (from one place to other) ?