Meet the water shortage
Provide 5 million m³ of extra available water each year without ignoring environmental costs.
Evidence to use
| Year | Annual demand (million m³) | Reliable supply (million m³) |
|---|---|---|
| 2020 | 18 | 22 |
| 2025 | 23 | 22 |
| 2030 | 27 | 22 |
The 2030 demand is a projection, not an observation. Reliable supply is the volume expected to be available through the year in this simplified model.
| Option | Extra available water (million m³/year) | Main issue |
|---|---|---|
| Leak repairs | 3 | Disruption during work |
| Reservoir | 8 | Valley habitat lost |
| Lower household use | 2 | Participation uncertain |
The budget
| Option | Up-front cost (£ million) | Extra water (million m³/year) |
|---|---|---|
| Leak repairs | 6 | 3 |
| Lower-use campaign | 2 | 2 |
| Reservoir | 18 | 8 |
The town has £10 million available now. New reservoir funding would need approval. Treat the predicted campaign saving as uncertain.
Different viewpoints
Resident
Repairs close roads for a while, but our water bills should stay affordable.
Ecologist
A reservoir would flood a valley habitat. We need surveys of the species and downstream effects.
Water engineer
Repairs can recover supply. We need to measure the savings and check demand during a dry year.
Possible approaches
- Combine leak repairs and lower use
- Build the reservoir
- Start with repairs and monitor demand
Compare effects on people, costs and the environment where they are relevant. Use the scale and date of the evidence carefully.
Try it yourself
Recommend an approach. Use evidence, compare an alternative and explain one condition that could change your decision.
One possible answer
Repairs plus the campaign cost £8 million and could provide 5 million m³ per year. That meets the original projected shortage within the budget. If the campaign saves only 1 million m³, the package leaves a 1 million m³ gap, so monitoring and another demand or supply measure are needed. A reservoir offers more water but cannot proceed within the current budget.
Check your answer: did you address the question, use accurate evidence and explain the link?
New evidence
A follow-up survey estimates that the campaign may save only 1 million m³ per year. Explain how this affects your recommendation.
Test your decision
What is the strongest argument against your choice? Would new evidence about cost, access or environmental effects change your recommendation?
Review your answer
Check that your recommendation meets the stated aim. Explain what the evidence supports, address an alternative fairly and make any uncertainty specific.