This is a model of the now-defunct "River Dam Model Works", kit #S-SS1, built by Ria. You can find this kit on eBay from time to time. It was a fairly straight-forward project. We cut a piece of thin plexiglass and used that as the base for the model to be able to make a nice mini-diorama out of the model. The last photo below shows the diorama placed on the Houston S Gaugers' wye module for a recent show.