River Formation/ Dam project

For Science class my table group had to do a project on the process of how dams are used to keep water in certain places. Our hypothisis was that "If we build a dam with foam blocks in a river, then it will stop the water and form a pool of water near the banks." To start out, we got a tub of sand a dug out a river. Then we placed the foam blocks in the middle of the river. Well our first experiment didnt work, because water was able to flow under the blocks. So we made a new experiment but placed play-dough under the cracks. This held the water fairly well. It leaked a little water through the play-dough and once there was too much water the wter eventually flowed right over the top. I think that the experiment was a succees because we constructed a fairly realistic dam that was able to hold the water back. If we were to do this project again I was use a bigger tub to make a larger river and dam. I was also use a more sturdy substance like cocking, to fill under the dam.