SNC1DO
Watershed Fantasy Island Activity
Oxford Dictionary defines 'watershed' as the following:
“noun - 1 an area or ridge of land that separates waters flowing to different rivers, basins, or seas. 2 a turning
point in a state of affairs. 3 Brit. the time after which programmes that are unsuitable for children are broadcast
on television.
A drainage basin is a landform that, along with gravity, guides rainwater and precipitation towards larger
waterways like rivers and oceans. Watershed can move water, and any minerals that water leaches, great
distances. A well known North American example of watershed is the Mississippi River. The Mississippi travels
through most of the United States' and runs down the center of the country. Notice how other tributaries (rivers)
and water routes converge (come together), like single lane roads leading to an 8 lane highway.
From an ecological standpoint, moving water carries valuable life sustaining nutrients and molecules.
Carbon, nitrogen, calcium and sometimes pesticides can dissolve or be carried by a drainage basin towards larger
waterways. Watershed can describe landforms a few kilometres in length or a few 100 kilometres in length.
Materials
 Modeling clay (1 stick)
- Thread (2 colours)
 Eye dropper with water
- Scissors
 Wax paper ~35 x 35 cm,
- Coloured pencils
 Metric ruler,
 Graph paper (.5 cm x.5 cm squares or similar)
Procedure:
1) Lay a piece of wax paper on the lab bench and use the modelling clay provided to build an island. The
island's maximum height should be no more than 3 cm. The island should have at least FOUR distinct
drainage basins. The shape of at least one basin should be very different from the others. Try not to
create lakes, craters, cone shaped peaks and other landforms that trap water.
2) Use an eyedropper with water to determine the approximate location of your island's largest rivers.
Gently drop water from 3-6 cm above different locations and observe the paths created when they trickle
off. If drops get 'stuck' simply add more water. You may reshape your island at any point during this
step.
3) Once you are satisfied with your island use a piece of coloured thread to indicate where the waterways
are. Press the thread into the clay to keep it in place. Use scissors to cut your thread.
4) Use a different colour thread to mark the boundaries of each water shed (at least four)
Be sure to show your boundaries like the diagram on the right. Boundaries lines are clean and continuous.
5) Use a pen or a pencil to carve out 2 – 5 tributaries (river branches) for each stream you have identified
with thread (the colour used to describe water flow)
6) Cut your island away from the wax paper and place it onto a piece of graph paper. Trace the island and
then, moving the island model away, draw the tributary and boundaries lines on the graph paper.
7) Your map should include the following: A north direction or compass rose, an island name, arrows
showing the flow of water, river names, and a hypothetical scale
Questions:
1) Using your scale, determine the length of the longest channel on the map (use thread to trace rivers that
are not straight). Show your calculations
2) Determine the area of the largest basin on your island.
Have Mr. Chawla take a picture of your watershed when you are finished answering your discussion questions. Dismantle your watershed and hand in your
island map (graph paper) and discussion questions in at the end of the period.
Rubric
Realistic landscape, tributaries and rivers
Island information (compass rose, island name, arrows showing
direction of flowing water, river names, hypothetical scale)
Questions
Total (App)
0 1 2 3
0 1 2 3 4 5
0 1 2 3 4
______ / 12