Not every raindrop runs straight to the outlet. Some water soaks into the ground, some is stored, and some returns to the air. The surface-routing model highlights downhill connections. It leaves out these other pathways so that the drainage divides and stream junctions are easier to see.
Water and oceans · Discover & try
Which river will this rain reach?
Reading level 4 of 5 · FluentChange
Word help
watershed
Land whose drainage connects to a shared outlet.
drainage divide
Higher land separating neighbouring surface drainage areas.
tributary
A stream that flows into another stream or river.
Watch · Try · Explain
See how it works
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Surface-drainage model; infiltration, evaporation, and underground routes are omitted.
What to look for
- Ridges separating surface routes
- Small streams joining larger ones
- A different boundary when the outlet changes
Explain what you noticed
What belongs to a river's watershed?
Keep this idea: A watershed connects an area of land to a chosen water outlet.
Follow the sources
- U.S. Geological Survey — Watersheds and Drainage Basins
- U.S. Environmental Protection Agency — Healthy Watersheds: Basic Information and Answers to Frequent Questions
Source material checked 2026-10-28. Explanations and activities by Nepedia. Agency source links do not imply endorsement.
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