The dams could be stacked 3 higher in a brick development. If you'll want to go better, widen the base similar to a pyramid. The higher you would like the wall height, the thicker the base must be. Stacking straight up will develop an unstable base and They might slide https://docs.google.com/drawings/d/18suWOLnxj46oZOfkZmRP9qd5QlSwz3BGXU3CzHM0Oew/edit?usp=sharing