Lesson 3 ended with a prediction; today it gets answered — then complicated. Two dry years hit one Pilbara operation, the allocation drops 20%, and students become summit delegates who must find 3,900 ML of savings without breaking the township, the mine, or the river. Somebody gives something up. That’s the lesson.
Harvest Lesson 3’s prediction first (“where does a Pilbara mine find millions of litres?” — groundwater was the seed). Then show the Water Use Data table for five seconds, hide it, and have students rank the five uses from memory before checking. Scale it: 19,500 ML ≈ 7,800 Olympic pools, and ore processing alone is ≈ 64%.
Two kinds of cause, named plainly: nature’s (variability — the dry years Lesson 3 promised) and ours (growing demand). The problem: five competing claims on one shrinking pool — ask early, “who speaks for the river?” Then the real toolkit: recycle, substitute fit-for-purpose water, efficiency, restrictions, new sources.
Teams of four, role cards dealt: Community · Mine Operations · Environment & River · Water Management (chair). The announcement lands: find 3,900 ML from the levers menu — every non-negotiable intact, every consequence written and owned, four signatures. Close with two teams presenting: same numbers, different pain.
Four prompts that answer the curriculum descriptor in their own voice: one natural cause and one human cause; the problem proven with a person from their summit; the smartest fix defended; and the line from our deal I’d defend to the Premier.