Geography K–10 · Years 5–6

Catchment model: where the rain goes

Geography (HASS F–6 sub-strand); NSW Geography K–10 (2015) Stage 3 focus area: Factors that Shape Places, whose four content groups are Factors that change environments, Environments shape places, Humans shape places and Bushfire hazard; none of those, and neither of the two Year 5 HASS Geography knowledge descriptors, names catchments, drainage or water. The two ACARA knowledge codes are cited for particular steps: the sand wall built beside the valley houses for AC9HS5K05 (managing severe weather events such as floods, and their consequences), and the farm and road markers for AC9HS5K04 (the influence of people on the characteristics of a place). The drainage mechanism stated in the concept has a descriptor of its own only at ACARA Year 7 (AC9HG7K01, the way water connects and changes places as it moves through environments), so at Stage 3 it is taught here as the groundwork for those two rather than as content in its own right, and that gap is stated rather than covered over.

PracticalLow risk

The idea

Rain that falls anywhere inside a catchment boundary drains to the same low point, carrying whatever is on the surface with it.

Safety card

Low riskAn adult supervises

Hazards

wet floor
marker stains

Controls

trays on a tarp
washable markers only

Note

No chemicals or heat are used. The activity is run under the school risk-assessment procedure; RiskAssess (riskassess.com.au) holds templates for school practicals and fieldwork. The NSW Department of Education Chemical Safety in Schools package is not triggered.

What you need

1 sheet of A3 paper crumpled and partly opened to make ridges and valleys, laid in a shallow tray
Washable markers (brown for a farm, black for a road, green for bush)
1 spray bottle of water (fine mist)
Second model: a 40 cm × 30 cm tray of damp sand shaped into two hills and a valley, small paper houses, a 500 mL jug

How to do it

On the paper landscape mark the highest ridge lines with a pencil; predict where water will collect and mark it with an X.
Colour a farm on one slope and a road on another with washable markers.
Mist the whole sheet with 20 sprays. Watch the colour run: trace the streams with a pencil as they form and mark where they join.
Compare the pencil ridge lines with where water flowed: draw the catchment boundary of the main low point.
In the sand tray build the same shape, place houses on the valley floor and on a hill, and pour 500 mL slowly onto the ridge. Record which houses are reached by water and how long it takes.
Rebuild and repeat with a sand wall (levee) beside the valley houses; record the difference.

What you should see

Coloured water collects at the lowest point of the paper landscape, which the class compares with its predicted X, and the farm and road colours arrive there mixed, showing that anything on the slopes reaches the outlet. The catchment boundary drawn after the rain is compared with the ridge lines drawn before it; where they differ, the water shows where the divide runs. In the sand tray the valley houses are reached first and the hill houses stay dry; the levee delays or diverts the water, and the class records the time difference in seconds.

What changes

What you change: presence of a levee
What you measure: time for water to reach the valley houses
What you keep the same: water volume and pour rate
landscape shape
house positions

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

Rain that falls on a hill stays on the hill.
Pollution on a road stays on the road.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Geography K–10 Syllabus (2015), NESA; current and taught in 2026, replaced from 2027. The outcome codes are not printed on the NESA landing page for this syllabus, which only links the document, so the url given is the syllabus document itself (geography-k-10-syllabus-2015.docx); the code and its outcome text were read in that document on 23 September 2026.GE3-2 GE3-3
Human Society and its Environment K–6 Syllabus (2024), NESA; implementation from 2027, not yet taught; code read on this page on 22 September 2026. The syllabus outcomes page used in this file for HSE-GEO-01, HS1-GEO-01 and HS2-GEO-01 renders Early Stage 1, Stage 1 and Stage 2 outcomes only and carries no Stage 3 block (checked 23 September 2026), which is why the Stage 3 code is cited from its focus-area content page instead.HS3-GEO-01
Australian Curriculum v9AC9HS5K05AC9HS5K04AC9HS5S05

Sources

The pages the author read to write this activity.

All Concept Studio activities