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TerraPrinter Classroom · Worksheet · Ages 10–15
Watersheds and rivers
Name Class Date
A watershed (or drainage basin) is all the land where rain drains into the same river or lake. The high ground between two watersheds is called a drainage divide. Use the Lake District model, with contour lines every 100 m.
Open a link in a web browser to see the model in 3D, or use the printed model from your teacher.
The highest mountain in England, Scafell Pike (978 m), is on this model. How many 100 m contour lines are there between sea level and its summit?
The long lakes and valleys spread out from the high ground in the middle, like the spokes of a wheel. What is this drainage pattern called?
Pick a spot on a hillside and put a small mark there. Which way would a raindrop landing there flow, and which lake would it reach? How did you decide?
With a washable marker, trace the drainage divide between two neighbouring valleys on your print. Describe where the divide runs.
The lakes here fill long, deep valleys. What do you think carved the valleys? (Hint: think about the last ice age.)
A farm high up in one valley spills fertiliser into a stream. Which places are affected? Which places are safe?
Draw a simple map of two valleys with a ridge between them. Add contour lines, the drainage divide, and arrows showing which way the water flows.
terraprinter.com/classroom/worksheet/watersheds/
TerraPrinter Classroom, CC BY 4.0: free to copy and adapt with credit.
TerraPrinter Classroom · For the teacher
Answer key: Watersheds and rivers
Learning goals
Define a watershed (drainage basin) and a drainage divide.
Predict which way water flows from contour lines and relief.
Recognise a radial drainage pattern around a central dome of hills.
Answers
The highest mountain in England, Scafell Pike (978 m), is on this model. How many 100 m contour lines are there between sea level and its summit?Nine (100 m to 900 m). The summit is 78 m above the 900 m line.
The long lakes and valleys spread out from the high ground in the middle, like the spokes of a wheel. What is this drainage pattern called?A radial drainage pattern.
Pick a spot on a hillside and put a small mark there. Which way would a raindrop landing there flow, and which lake would it reach? How did you decide?Answers depend on the spot. Water flows straight downhill, across the contour lines from higher to lower ones, into the nearest valley and on to that valley's lake.
With a washable marker, trace the drainage divide between two neighbouring valleys on your print. Describe where the divide runs.Along the tops of the ridges, joining the highest points between the two valleys. Rain on one side flows to one lake, rain on the other side to the other.
The lakes here fill long, deep valleys. What do you think carved the valleys? (Hint: think about the last ice age.)Glaciers. In the last ice age, ice flowed out from the high ground and deepened the valleys. When the ice melted, water filled the hollows to make the lakes.
A farm high up in one valley spills fertiliser into a stream. Which places are affected? Which places are safe?Everything downstream in the same watershed: the stream, the lake it flows into and the river below. Places over the drainage divide, in other watersheds, are not affected.
Draw a simple map of two valleys with a ridge between them. Add contour lines, the drainage divide, and arrows showing which way the water flows.Contour lines bend into V shapes pointing uphill in each valley. The divide runs along the ridge top. Arrows point down each valley, away from the divide.
Before the lesson
Print the models at 150 mm wide, 0.2 mm layers, 10–15% infill, no supports. Contour lines are raised ridges every 100 m. The lakes are cut into the terrain, so they show up even on a single-colour print. Measurements on the sheet assume the 150 mm size. Students' measured answers will vary a little with how they measure. Discussion questions and a hands-on activity for this topic: terraprinter.com/classroom/#watersheds
