One activity that causes instability in the stream channel is the removal of gravel from the river. For many years gravel has been extracted from river basins for road work or for building materials. In the Lake Champlain Basin this gravel is of high quality and because it does not need to be transported long distances to work sites it is of low cost.
But the amount of gravel in a stable river is a careful balance of the river's work of transporting water and sediment. If you take out gravel, the river works harder to fill in what was lost. (See the Stream Channel Stability Model)
In this model a turntable is housed in a painted circular box. When the fish handle on top is turned various species of trout swim into view on the side panels and various pictures describing the effects of gravel mining appear on top. These pictures are accompanied by descriptive materials.
In this web version you can turn the model by clicking on the wooden fish at the right or by clicking the "Next" button below.
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