Course 245 · Life course 67

Trace Water Through a Watershed

A fictional watershed diagram tracking runoff, infiltration, groundwater and pollution paths, with a supported upstream/downstream prevention choice. Six introductory lessons use supplied practice cases.

Before you start

Use paper or a free text document; every core input is supplied in the lessons.

Explain Places with Human and Physical Geography See everything you’ll need

Free download · Original practice data · No external account required. Download the starter pack

What you’ll leave with

A fictional watershed diagram tracking runoff, infiltration, groundwater and pollution paths, with a supported upstream/downstream prevention choice.

Start course Start without an account. Sign in to save lesson progress across devices.

Your project

Start with the practice files. Build your project one lesson at a time.

Practice files are free without an account. Sign in to save your project record in My Proof: a description, checklist, and optional work link. Keep the original files in your own app or notebook; saving a project record does not upload them.

Get your materialsDownload practice filesSupplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.
Make your projectView the project checklist Work in your own notebook, document, or software. Use the supplied practice examples when you prefer.
Keep a private recordSave a project record Sign in to save a description and checklist, then return to update them.

Course handbook

Know the route before you begin.

Here’s what you’ll need and what you’ll make. You can return to this guide during any lesson.

Who this is for

Learners aged 14+ building subject foundations and practical independence. Adults can use the same supplied cases.

Prepare before lesson one

Use paper or a free text document; every core input is supplied in the lessons.
A basic calculator is optional; show the method, units and checks.
Suggested earlier course: Explain Places with Human and Physical Geography

Your final project

Finish with proof you can use.

A fictional watershed diagram tracking runoff, infiltration, groundwater and pollution paths, with a supported upstream/downstream prevention choice.

Save a project record in My Proof

See project checklist and review criteria

Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.

What to include

Draw outlet-specific and nested drainage boundaries.
Label water stores, phase changes and land/plant routes.
Balance supplied rain budgets and compare fractions.
Read groundwater/stream exchange cross-sections.
Trace a possible pollution route without inventing treatment.
Explain a responsible paper prevention choice and include all changed cases.

Review and revise

Use these criteria to check your work and choose what to improve.

Method: applies the course-specific rules to the supplied cases with visible intermediate work.
Accuracy: results agree with the stated facts, units, boundaries and independent checks.
Reasoning: explains why the result follows and identifies a limitation or unresolved question.
Transfer: completes changed cases and revises the final project when a relevant assumption changes.

Three ideas to help you along the way

Three useful ideas

The rules behind the steps.

Check the specific conditions

A surface watershed is the land area whose runoff drains toward a selected outlet. Ridges or other divides can separate runoff destinations. A watershed boundary depends on the outlet chosen: a small stream basin can lie within a larger river basin. Groundwater boundaries can differ from the simple surface divide.

Follow the supplied evidence

The water cycle moves water among surface, underground and atmospheric stores. Evaporation converts liquid to vapor; condensation forms liquid droplets; precipitation returns water to the surface; infiltration enters the ground; runoff moves over it. Water can stay in a store for different times, so the cycle is not one fixed sequence or speed.

Keep the limits visible

Runoff can pick up material from dispersed land sources and carry it through drains, streams or infiltration pathways. A possible route does not prove that a particular source caused a measured problem. Trace source, transport, receiving water and missing evidence; never handle unknown material to complete this lesson.

What do these words mean?

Key words

Key terms worth knowing.

Watershed: Surface drainage area contributing to a chosen outlet.
Divide: Boundary separating surface runoff destinations.
Infiltration: Entry of water from the surface into the ground.
Runoff: Water moving over the land surface.
Aquifer: Geological material that stores and transmits groundwater.
Nonpoint source: A dispersed source whose material can be transported by routes such as runoff.

Your route

6 lessons.
One useful project.

Work in order the first time. Each lesson makes something the next lesson can use.

Use the tools

Tools to help you practice.

See all tools

ZIP · practice files

Trace Water Through a Watershed practice files

Supplied practice cases, a blank working record, complete lesson instructions, and annotated worked examples.

Text worksheet

Your course project worksheet

A downloadable text worksheet with each lesson’s working output, space for your answers, and the shared final-project checklist. Save your own copy.

Source transparency

Sources and further study.

Explore the references behind the lessons and take your learning further. Source notes explain access and reuse.

USGS: watershed boundaries and outlets

Source & access notes · checked 2026-10-01