The Problems and Benefits Created by the Spread of the Water Hyacinth in Kenya — IELTS Reading Answers

If you are preparing for IELTS Academic Reading and searching for the water hyacinth Kenya IELTS reading answers, you are in the right place. This is one of the newer nature-and-environment reading passages, and very little practice material exists for it online. In this post from Pacific Educational Consultant, you get the full reading passage, all 13 questions, a clean answer key, and a word-by-word explanation of every answer so you understand why each answer is correct — not just what it is.

Bookmark this page and try the passage under exam conditions (20 minutes) before you check the answers below.

Quick Answer Key (Water Hyacinth in Kenya IELTS Reading)

If you just want to check your score fast, here is the complete answer key. Scroll down for the full explanations.

Reading Passage: The Problems and Benefits Created by the Spread of the Water Hyacinth in Kenya

Water hyacinth (Eichhornia crassipes), an aquatic plant native to South America, first appeared in countries in Africa in the early 1900s. Scientists there called it the 'world's worst aquatic weed', after it spread from the southernmost tip of Africa in the early 1900s and started obstructing major dams and rivers.

In east Africa the plant arrived with Belgian colonists in Rwanda, who liked the look of its glossy leaves and delicate purple flowers floating in their ponds. But by the 1980s, it had 'escaped' out of the country via the Kagera river and made its way downstream to Lake Victoria. There, with no natural predators and perfect temperature conditions, the plant began spreading in the open water, blocking fishing routes and providing a new habitat for disease-carrying mosquitoes.

For the women who smoke fish from the lake to sell it has meant declining income, as the boats that once brought the fish to shore by the hundreds struggle to navigate through the mass of plants. But water hyacinth isn't their only headache. In order to smoke the fish that they buy, they must gather huge quantities of firewood, sometimes walking as far as 10km each way to collect enough to complete their work. And each day as they cook, they breathe in the thick, grey smoke. About three out of four families in Kenya depend on wood or charcoal to cook their daily meals, and the rate is even higher in rural areas, Kenya's latest demographic and health survey shows.

Using solid fuels like these for cooking increases indoor pollution. The World Health Organization estimates that about 14,300 Kenyans die annually as a result of indoor air pollution — most of which is caused by cooking and heating sources.

Some years ago, on the shores of Lake Victoria, huge piles of water hyacinth that villagers had taken out of the water in an attempt to clear it were a common sight. But buried in those decaying waxy leaves was a renewable energy gold mine. It turns out the floating plant isn't just good at spreading — its foliage also contains a high ratio of carbon to nitrogen. It's a magic combination that has captivated researchers' imaginations since as early as the 1980s when, across the world, they began to explore its potential as a biofuel. Just about 4kg of the dried plant would be enough to cater for a large family's daily energy needs, early research predicted.

In 2014, Nigerian academics announced they had got better yields of biofuel gas when they mixed the plant with chicken manure. A few years later, Kenyan scientists confirmed what their Nigerian peers and others had already found: manure worked to improve the process of converting the weed into gas.

In 2018, the technology came to a village on the shore of Lake Victoria, called Dunga. The project promised a two-for-one solution to the dual menaces of the water hyacinth and dependence on firewood. The community received a pair of donated biogas digesters — machines that would transform a mix of water hyacinth and cow dung into biogas for cooking.

The digesters work a bit like a stomach. The mixture goes in one end — think of it as a mouth — and over the next 20 to 30 days, it goes through a fermentation process and breaks down, giving off gas that comes out the other end. From there, the clean-burning gas is passed through pipes to the point of use, just like traditional domestic gas. In Dunga, the machines produce enough gas to serve about 60% of the village's population. It is used in domestic stoves and for other household tasks such as purifying water and incubating chicks.

The project is testing whether biogas can provide an effective alternative to firewood and charcoal in rural Kenyan communities. Results indicate that the programme seems to be working. The women who smoke the lake fish are already getting sick less often. Besides, they don't have to devote a lot of time every day to gathering firewood, which is a great relief. As a result, they're able to make more money for their families from other enterprises.

Kanyiva Muindi is an epidemiologist and air pollution research fellow at the African Population and Health Research Centre in Nairobi. She says families who switch to the smokeless cooking method could expect fewer respiratory diseases. Women, young girls and children are particularly vulnerable because they are the ones who cook in the kitchen or outside over fires.

How much better the biogas stoves will be for the community's health still needs more research, says Dominic Kahumbu Wanjihia, Biogas International's chief executive. But unless the price of the machines drops, it's pretty clear that most communities will never be able to afford any, since they sell for about $750.

Kanyiva says affordability is a challenge worth addressing, given the huge health and environmental dangers posed by 'dirty' fuels such as wood, charcoal and kerosene. If biogas could become affordable on a large scale, she says it 'would be life-changing for millions on the African continent and beyond'.

Questions 1–13

Questions 1–7 — TRUE / FALSE / NOT GIVEN

Do the following statements agree with the information given in the Reading Passage?

• Write TRUE if the statement agrees with the information
• Write FALSE if the statement contradicts the information
• Write NOT GIVEN if there is no information on this

1. Water hyacinth was introduced as a decorative plant in east Africa.
2. Fishermen took some water hyacinth plants to Lake Victoria.
3. It is now difficult to force boats through the thick water hyacinth on Lake Victoria.
4. Chemicals produced by the water hyacinth plants are affecting the numbers of fish in Lake Victoria.
5. Cooking with charcoal has been proved to be even worse for people's health than cooking with wood.
6. People found it impossible to remove much water hyacinth from Lake Victoria.
7. Scientists started investigating the possibility of using water hyacinth to generate biogas in the last century.

Questions 8–10 — Flow-chart Completion

Complete the flow-chart below. Choose NO MORE THAN TWO WORDS from the passage for each answer.

Generating biogas for domestic use in Dunga

• First, place water hyacinth together with some (8) …………… into a digester.
• Leave the mixture until the (9) …………… is completed.
• Capture the gas emitted by the digester and use (10) …………… to transport it to individual homes.
• Then use the gas for cooking as well as making water fit for human consumption.

Questions 11–13 — Note Completion

Complete the notes below. Choose ONE WORD ONLY from the passage for each answer.

Cooking with biogas in Dunga

Benefits for the women in the village of cooking with biogas

• no need for them to spend so much (11) …………… collecting fuel
• they can focus on different tasks that bring in (12) ……………
• they are less likely to experience certain diseases connected to burning wood

Drawbacks of changing to biogas

• the (13) …………… of the digesters is beyond the reach of most villages

Answers with Detailed Explanations

Below is the full breakdown. For each answer you get the keyword location in the passage and the exact reasoning, which is the fastest way to raise your Reading band.

Question 1 — TRUE

Statement: Water hyacinth was introduced as a decorative plant in east Africa. Where: Paragraph 2 — "the plant arrived with Belgian colonists in Rwanda, who liked the look of its glossy leaves and delicate purple flowers floating in their ponds." Why: The colonists valued its look and kept it floating in their ponds. Growing a plant for its appearance is exactly what "decorative" means, so the statement agrees with the passage. TRUE.

Question 2 — FALSE

Statement: Fishermen took some water hyacinth plants to Lake Victoria. Where: Paragraph 2 — "by the 1980s, it had 'escaped' out of the country via the Kagera river and made its way downstream to Lake Victoria." Why: The plant reached the lake on its own — it escaped via the river and drifted downstream. No person, and certainly no fisherman, carried it there. The statement contradicts the passage. FALSE.

Question 3 — TRUE

Statement: It is now difficult to force boats through the thick water hyacinth on Lake Victoria. Where: Paragraph 3 — "the boats that once brought the fish to shore by the hundreds struggle to navigate through the mass of plants." Why: "Struggle to navigate through the mass of plants" is a direct paraphrase of "difficult to force boats through the thick water hyacinth." The meaning matches. TRUE.

Question 4 — NOT GIVEN

Statement: Chemicals produced by the water hyacinth plants are affecting the numbers of fish in Lake Victoria. Where: Paragraph 2–3 discuss blocked fishing routes and falling income, but never chemicals. Why: The passage links the plant to blocked routes and declining income, not to any chemicals reducing fish numbers. Since this specific claim is never stated, there is no information to confirm or contradict it. NOT GIVEN.

Question 5 — NOT GIVEN

Statement: Cooking with charcoal has been proved to be even worse for people's health than cooking with wood. Where: Paragraph 3–4 mention both "wood or charcoal" and indoor pollution deaths, but never compare the two. Why: The passage groups wood and charcoal together as harmful "solid fuels." It never ranks one as worse than the other. A comparison that the text does not make is always NOT GIVEN.

Question 6 — FALSE

Statement: People found it impossible to remove much water hyacinth from Lake Victoria. Where: Paragraph 5 — "huge piles of water hyacinth that villagers had taken out of the water in an attempt to clear it were a common sight." Why: Villagers did remove the plant — in huge piles, so large they were a common sight. Removal clearly happened, so "impossible to remove much" contradicts the text. FALSE.

Question 7 — TRUE

Statement: Scientists started investigating the possibility of using water hyacinth to generate biogas in the last century. Where: Paragraph 5 — "since as early as the 1980s when, across the world, they began to explore its potential as a biofuel." Why: Research began in the 1980s, which falls in the 20th century — i.e. "the last century." The statement matches. TRUE. Exam tip: "the last century" = the 1900s. The 1980s is inside it, so this is TRUE, not NOT GIVEN.

Question 8 — cow dung

Sentence: "machines that would transform a mix of water hyacinth and cow dung into biogas for cooking." Why: The digester takes water hyacinth plus something else. That "something else" is cow dung. Two words, straight from the passage. ✅ (Watch out for "chicken manure" — that was Nigerian research in 2014, not the Dunga digesters.)

Question 9 — fermentation (process)

Sentence: "over the next 20 to 30 days, it goes through a fermentation process and breaks down." Why: The mixture is left until the fermentation process is completed. Both "fermentation" and "fermentation process" are acceptable within the two-word limit. ✅

Question 10 — pipes

Sentence: "the clean-burning gas is passed through pipes to the point of use." Why: The gas is transported to homes through pipes. The answer to "use ……… to transport it" is pipes. ✅

Question 11 — time

Sentence: "they don't have to devote a lot of time every day to gathering firewood." Why: "Spend so much ……… collecting fuel" paraphrases "devote a lot of time … to gathering firewood." The missing word is time. ✅

Question 12 — money

Sentence: "they're able to make more money for their families from other enterprises." Why: "Tasks that bring in ………" = the other enterprises that let them make more money. One word only: money. ✅

Question 13 — price

Sentence: "unless the price of the machines drops … they sell for about $750." Why: The drawback is affordability — the price of the digesters puts them out of reach of most villages. ✅ (Not "cost" — the passage uses the exact word "price," and note-completion needs the word from the text.)

Vocabulary from the Water Hyacinth IELTS Passage

Building topic vocabulary is one of the fastest ways to boost your Reading and Writing bands. Here are useful words and collocations from this passage:

• aquatic weed – a fast-growing water plant, usually unwanted
• natural predators – animals that would normally control a species' spread
• obstructing – blocking; getting in the way of
• renewable energy – energy from sources that do not run out, e.g. biogas
• biofuel / biogas – fuel or gas produced from organic material
• fermentation – the chemical breakdown of material by microorganisms
• digester – a machine that breaks down organic matter to produce gas
• indoor air pollution – harmful smoke or particles inside a home
• respiratory diseases – illnesses affecting breathing and the lungs
• affordability – how easily people can pay for something

How to Approach This Passage (Strategy Tips)

TRUE / FALSE / NOT GIVEN: The single biggest trap here is confusing FALSE with NOT GIVEN. FALSE means the passage says the opposite (Q2, Q6). NOT GIVEN means the passage never makes the claim at all (Q4, Q5). When a statement adds a new detail — "chemicals," "proved worse than" — that the text does not mention, choose NOT GIVEN.

Flow-chart & note completion: Always obey the word limit ("NO MORE THAN TWO WORDS," "ONE WORD ONLY"). Copy the word exactly as it appears — do not change "price" to "cost" or "pipes" to "pipe." These questions follow the order of the passage, so once you find Q8, Q9 and Q10 come soon after.

Time management: Aim for 18–20 minutes on this passage. Scan for names and numbers (Dunga, 2018, $750, 20 to 30 days) — they act as fast anchors to locate answers.

Practice More IELTS Reading with Pacific Educational Consultant

This passage combines an environmental problem (an invasive weed) with a human-development solution (biogas), which is a very common theme in recent IELTS Academic tests. If you found the water hyacinth Kenya IELTS reading answers helpful, try timing yourself on the passage first and using the explanations only to review your mistakes.

Frequently Asked Questions

Q: What is the water hyacinth IELTS reading passage about?

It describes how the invasive water hyacinth plant damaged fishing and health around Lake Victoria in Kenya, and how villagers in Dunga now turn the weed into clean biogas for cooking.

Q: Is this a real IELTS Academic Reading passage?

Yes, it is a nature-and-environment style Academic Reading passage with TRUE/FALSE/NOT GIVEN, flow-chart and note-completion questions — the exact formats you will see on test day.

Q: What band level is this passage?

It suits candidates targeting Band 6.0 to 8.0. The TRUE/FALSE/NOT GIVEN section is the most challenging part.