4.2.3—Water supply increase needs
- Syllabus
- First assessment 2026
- Objective
- 4.2.3
- Level
- HL
Find Water Demand before Expanding Supply
Identify which sector is driving demand before choosing between efficiency and new supply.
Separate household, irrigation, livestock and industrial use, then check timing, leakage and return flows. Fixing the driver can meet need with less withdrawal than building capacity.
If irrigation dominates summer demand, drip systems and crop choice may help more than a new household reservoir.
Remaining demand after leakage and efficiency measures, with ecological and recharge limits included.
Lower use per unit can cause expansion; measure total basin withdrawal, not efficiency alone.