This activity could be used in relation to the Water Context on STEM Central.

A dam is a structure that stops water from flowing. Usually, a dam is built to redirect the water or to use the water power to generate electricity. Building a model dam is a great idea for STEM work, especially if you research the purposes of various dams and display the information along with your model. With a few simple materials, you can make a dam that works like the real thing. Why not take it further and explore microgeneration too?  More information is available by following this link.