Groups of 8th grade Earth Science students were asked to prepare posters summarizing their knowledge of the water cycle prior to a unit on ground water. Misconceptions of the occurrence of ground water illustrated on the posters indicated widespread belief in underground rivers flowing within a tunneled earth, even though students lived far from a karst terrane and also believed in flat water tables. To suggest alternative conceptions, students were provided with materials to construct wet models of ground water occurrence. A model consists of a 3 ft by 1 in clear plastic tube filled with yellow silty sand, held upright in a plastic container filled with gravel. An empty narrow plastic tube inserted within the gravel provides a well. When the container is filled with dyed water, water rises in the well and also appears in the container as a water table. Water also rises in the sand, forming a capillary fringe as tall as 2.5 ft, with an irregular wetting front. After constructing the model, students were able to improve their posters to reflect a more realistic conception of the water table and ground water occurrence.