Drainage in Rwanda
Senior 2 · Geography and Environment
Drainage in Rwanda
Lesson 3 of 4
18 min
The tap water in a Kigali home and the rice on a Bugarama farm both come from Rwanda's water bodies. So do the sambaza fried on the shore at Rubavu and the electricity from the Ntaruka power station. Water bodies are the rivers, lakes and swamps of an area. Knowing what they provide lets you judge what is lost when they are polluted or drained. This lesson sets out their uses with Rwandan examples.
| Use | Rwandan examples |
|---|---|
| Water supply | Treatment plants draw water from the Nyabarongo and other rivers for Kigali's homes and industries; springs and lakes supply rural areas. |
| Hydroelectric power (HEP) | The Ntaruka station uses the 100 m drop over a 600 m stream from Lake Burera to Lake Ruhondo (about 11.5 MW). Other stations are on the Mukungwa and Nyabarongo, and one at Rusumo Falls on the Akagera is shared with Burundi and Tanzania. |
| Methane gas | Methane dissolved deep in Lake Kivu is extracted to generate electricity; the first stage of the KivuWatt project supplies about 26 MW. |
| Irrigation | Marshland rice in valley floors such as Bugarama and along the Nyabarongo; vegetables watered from rivers and valley dams in the east. |
| Fishing | Lake Kivu's sambaza, a small sardine brought from Lake Tanganyika, plus tilapia and catfish in many lakes. |
| Transport | Boats link Rubavu, Karongi and Rusizi on Lake Kivu, and islands on Burera and Ruhondo. |
| Tourism and recreation | Beaches at Rubavu and Karongi, boat trips on Lake Ihema, bird watching in the wetlands. |
| Wildlife habitat | Papyrus swamps shelter the papyrus gonolek, the grey crowned crane and the sitatunga antelope. |
| Natural regulation | Swamps act as the land's "kidneys": they store floodwater, release it slowly in the dry season and filter out silt and waste. Lakes moderate local climate. |
| Raw materials | Sand and clay for building and bricks; papyrus for mats; peat from some marshes burned to make electricity. |
| Boundaries | Lake Kivu and the Rusizi (DR Congo), and the Akanyaru and Akagera (Burundi and Tanzania), mark borders. |
Fish production on Lake Kivu fell from 24,199 tonnes in the 2017–18 season to 16,194 tonnes in 2019–20. Calculate the percentage fall and suggest one cause.
Resources that seem unlimited can shrink quickly when they are over-used. That is why the next lesson turns to managing them.
Tip
Exam technique. Group the uses into economic (power, fishing, irrigation, transport, tourism, raw materials), social (domestic water, recreation) and environmental (habitat, flood control, filtering, climate). Give a named Rwandan example for each point; a bare list scores poorly.
Solution: the water drops about 100 m over a short distance (about 600 m), which gives a strong fall to turn turbines.
Solution: sambaza (a small sardine brought from Lake Tanganyika).
Solution: like kidneys they filter the water passing through them, trapping silt and waste, and they regulate its flow.
Solution: methane for electricity and tourism (also transport).
Solution: 200 ÷ 800 × 100 = 25%.
Summary
Sources and credits
The table of uses, the worked example and the practice items are written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
