It can be useful and fun to make a model for any 3-D project; but for a public artwork it is an essential tool. Here is one of my early "sketch" models for this project.
A sketch, or rough draft, model allows me to test ideas quickly. I'm looking at the proportions, the construction issues, the kinds of materials that I might use, the potential challenges.
In this model, the tubes represent 12" diameter Sonotube concrete forms. (Yes, they are toilet paper tubes; the scale here is: one TP tube to one foot). The black shapes on top of the short pillars represent dark granite or marble, engraved with words and images that reflect the importance of the pond and habitat. Examples might include images of the creatures that inhabit this habitat, which the youth are studying. Pond snails, frogs, minnows, butterflies, trees, plants...
The rough cardboard shapes represent the kind of stone and boulders which currently surround the pond. I'd like to find more of these, so that the stone at the outfall will be similar to the stone at the pond.