The terrible smell from the River ThamesThe river that flows through London, England's capital city. filled the Houses of ParliamentIn the UK, the place where British lawmakers meet to debate and make new laws. . MPsMembers of Parliament. MPs are elected to represent people in 650 different geographical areas.  were forced to hold handkerchiefs over their noses.

The smell came to be known as "the great stink". It was caused by sewageWaste matter such as human waste. which had been building up in the river for hundreds of years. In the summer of 1858 there was a heatwaveA period of abnormally hot weather. which caused a terrible smell.

The horrific pong drove MPs to pass a new lawA rule that everyone must follow. in record time. London was given £3m to construct a new sewage system.

Now, some think we might be about to enter a new "great stink". Today London still depends on the same sewage system, even though its population is three times as big. ExtremeVery great, or beyond what is expected. rainfall caused by climate changeLong-term shifts in temperatures and weather patterns. Human action is a major cause of climate change. has put even more pressure on the system.

More and more sewage is being released into rivers. Now river pollutionWhen harmful or dangerous things are put into the environment. is raising new fears for public health.

The problem is not just in London. This week, journalistsPeople whose job it is to report on the news. found out that millions of litres of raw sewage were illegallyIn a way that is against the law. pumped illegally into Lake Windermere in the Lake DistrictA mountainous area of northwest England. It contains the country's largest natural lake, Windermere. in February. Sewage can make the water turn green.

In England, raw sewage was released into rivers and seas for over 3.6 million hours over the past year. That is more than double the figure for the previous 12 months.

Is this a new great stink?

Yes! The amount of sewage being released into rivers and the sea is terrible. Solving this problem will take years and millions of pounds of spending on new sewage systems, just like in 1858.

No! No great stink has overtaken London - but it might be better if it had. A horrible smell would force politiciansSomeone whose job it is to be involved in running a country. Politicians try to persuade people they have the best ideas to run the country. to act. For now, many people never think about rivers, so the problem keeps getting worse.

River Thames - The river that flows through London, England's capital city.

Houses of Parliament - In the UK, the place where British lawmakers meet to debate and make new laws.

MPs - Members of Parliament. MPs are elected to represent people in 650 different geographical areas. 

Sewage - Waste matter such as human waste.

Heatwave - A period of abnormally hot weather.

Law - A rule that everyone must follow.

Extreme - Very great, or beyond what is expected.

Climate change - Long-term shifts in temperatures and weather patterns. Human action is a major cause of climate change.

Pollution - When harmful or dangerous things are put into the environment.

Journalists - People whose job it is to report on the news.

Illegally - In a way that is against the law.

Lake District - A mountainous area of northwest England. It contains the country's largest natural lake, Windermere.

Politicians - Someone whose job it is to be involved in running a country. Politicians try to persuade people they have the best ideas to run the country.