Water Cycle Model

When we studied water, I couldn't exactly build streams and rivers, though I did contemplate using the hose to simulate water flow, but instead I opted to used yarn.

The 'water' came down out of the mountain in streams, joined to make a river, fell as a water fall, and made a delta as it flowed into our lake.

This isn't ground breaking, but it was impressive to the littles and it gave a great 3D representation of water--oh, and I held the skein of yarn up to represent a cloud, so we got the rainfall/evaporation part covered too!