Key Idea: Topic 7.4 is about how the water in a drainage basin is managed for the future, and why that always means choosing between competing users. It pulls together two ideas: 7.4.1 — integrated management & dams: a dam is the most powerful tool a manager has — it stores water for power, supply and flood control — but it creates winners and losers by stakeholder. Integrated drainage basin management (IDBM) answers that by planning the whole basin as one system, coordinating every user and riparian country. 7.4.2 — stakeholders, conflict & wetlands: the same water is wanted by farmers, cities, industry, fishers, governments and conservationists, so management creates conflict from competing demands and unequal power. Wetlands give free ecosystem services but are easily drained — the basin's future depends on balancing all the stakeholders sustainably. This is Option A (Freshwater) content, examined on Paper 1. Each option carries map/figure reads and a short structured Explain, then a [10] extended-answer (Examine / Evaluate / Discuss). SL answers 2 options, HL answers 3 — the same questions at both levels.
🏞️ 7.4.1 — Integrated management & dams
A drainage basin rarely sits inside one town or one country, so its water must be shared. A dam stores water in a reservoir and lets the operator control downstream flow — bringing power, irrigation and flood control, but flooding land upstream and starving downstream users of water and silt. Integrated drainage basin management (IDBM) manages the whole basin as one system, coordinating all users and riparian countries for fair, sustainable water use instead of acting scheme by scheme. The skill examiners test is reading a thematic map (dams along a river, or managed aquifer recharge sites by region), then Identify or Outline an upstream-to-downstream impact and pin it to a stakeholder.
A large dam — benefits and costs by stakeholder
| Stakeholder | Benefit of the dam | Cost of the dam |
|---|---|---|
| City / water company | Reliable year-round water + hydro-electricity | High build cost; reservoir silts up over time |
| Upstream communities | Irrigation water and flood control | Land and homes flooded; people displaced |
| Downstream farmers | Steadier flow for irrigation | Less silt reaches fields, so soils lose fertility |
| Fishers | New reservoir fishery upstream | Dam blocks migration; downstream catch falls |
| The environment | Stores flood water; clean energy | Drowned valley ecosystems; sediment-starved water below |
Read the key first. MAR sites cluster near cities because that is where water demand — and the storm-water to recharge with — is greatest.
🔒 Interactive diagram
Explore the labelled diagram, charts and maps for this topic in study mode.
Key terms — management & dams
- Integrated drainage basin management (IDBM) — managing the whole basin as one unit, coordinating all users and countries.
- Dam / reservoir — a barrier across a river that holds water in an artificial lake, controlling downstream flow.
- Riparian country — a country the river flows through, with a claim to its water.
- Managed aquifer recharge (MAR) — deliberately topping up underground water stores with surface or recycled water.
- Upstream / downstream — nearer the source / nearer the mouth; what happens upstream affects everyone below.
Tip: For Outline and Explain marks, never stop at the effect: upstream dam → traps silt → downstream soils lose fertility → farmers' yields fall. Say who is affected and why. On the IDBM Explain, give two developed advantages of the whole-basin plan — listing one dam's benefits is capped.
🤝 7.4.2 — Stakeholders, conflict & wetland futures
A stakeholder is any party with an interest in how water is managed. Different stakeholders want different things from the same river, lake, aquifer or wetland — so management creates conflict from competing demands (drinking, farming, energy, fishing, nature) and unequal power (a government or big firm can override a small village or a wetland). Wetlands (marsh, swamp, floodplain, delta) sit at the centre of the conflict: they give free ecosystem services — flood control, water cleaning, carbon storage, wildlife — yet are easily drained for land. A sustainable future needs the stakeholders balanced, which is exactly what the [10] essay asks you to weigh.
Stakeholders in a drainage basin — what they want
| Stakeholder | What they want from the water | Typical conflict |
|---|---|---|
| Farmers | Cheap, reliable water to irrigate crops | Take so much the river runs low for others |
| Urban residents | Clean, safe piped drinking water | Compete with farms and industry in droughts |
| Industry / energy | Water for cooling, processing or hydropower | Pollute or dam the river, harming downstream users |
| Fishers | A healthy, flowing river and wetlands | Lose catch when water is diverted or polluted |
| Government | Economic growth, flood safety, votes | Favour big schemes (dams) over local needs |
| Conservationists | Wetlands and wildlife protected | Clash with farming and building that drain wetlands |
| Downstream / other countries | A fair share of a shared river | Upstream use leaves too little water flowing on |
Key terms — conflict & wetlands
- Stakeholder — any party with an interest in a water resource; each has a want and a level of power.
- Conflict — a clash when stakeholders want incompatible things from the same water (e.g. irrigation vs fishing).
- Wetland — saturated land — a flood store, water filter, carbon sink and wildlife habitat.
- Ecosystem services — the free benefits a wetland gives: flood control, water cleaning, carbon storage, food.
- Transboundary basin — a river, lake or aquifer shared across international borders, so no one government controls it.
- Ramsar Convention — the 1971 treaty under which countries protect wetlands of global importance.
Example: Three Gorges (Yangtze, China) — huge power and flood control, but about 1.3 million people relocated: a dam whose costs and benefits fall unevenly. Grand Ethiopian Renaissance Dam (Nile) — Ethiopia dams the Blue Nile upstream while Egypt fears losing its supply: a transboundary clash. The Aral Sea (Central Asia) — rivers diverted for cotton until the inland sea shrank, wrecking fishing: over-abstraction by one sector. The Sudd (White Nile, South Sudan) — a vast wetland where draining it for downstream farming pitted herders and conservationists against downstream states.
✍️ IB-style questions
Explain two advantages of managing a river under an integrated drainage basin management plan rather than scheme by scheme.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Examine how conflicts between different stakeholders make a drainage basin's water hard to manage sustainably.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
✅ Quick self-check
Tap each card to reveal the answer.
What is integrated drainage basin management? Managing the whole basin as one system — coordinating all users and riparian countries from source to mouth — for fair, sustainable water use, instead of acting scheme by scheme.
How can an upstream dam harm downstream farmers? The dam traps silt and water in its reservoir, so less reaches downstream fields — soils lose fertility and there is less irrigation water, cutting yields.
Why does managing water cause conflict? Because stakeholders have competing demands (drinking, farming, energy, fishing, nature) and unequal power — one party's gain is another's loss.
Why are wetlands worth protecting? They give free ecosystem services: flood control, water filtering, carbon storage and wildlife habitat — yet are easily drained for land.
What caps the marks on the option questions? On the Explain, writing only about one dam's benefits. On the [10] essay, listing conflicts with no named case study or judgement — top band needs named evidence and a justified conclusion.
🎯 Highest-yield exam reminders
Exam Tips
- IDBM = manage the WHOLE basin as one system, all users and riparian countries together.
- A dam makes winners (power, water, flood control) and losers (flooded land upstream, lost silt downstream).
- On the IDBM Explain [6], give two developed advantages of the PLAN — listing one dam's benefits is capped.
- A stakeholder has a WANT and a level of POWER; conflict = competing demands + unequal power.
- Wetlands give flood control, water cleaning, carbon storage and habitat — name the ecosystem service AND its effect.
- On the [10] option essay: map the stakeholders, weigh For/Against with a NAMED case + data (Three Gorges, the Nile/GERD, the Aral Sea, the Sudd), and end on a justified judgement.