Origin and Evolution of the London Sewer System

The London sewer system is one of the most recognizable and significant engineering feats in the history of urban infrastructure. Interestingly, however, it was not initially created for the purpose it is most commonly associated with - sewage management. Instead, the first sewers in London were designed to handle storm water and prevent flooding. This reflects the changing needs and technological advancements of a rapidly growing city in the 19th century.

Origins: Storm Water Management

London's initial sewers were based on the ancient waterways that crisscrossed the city, such as the Fleet and the Walbrook. These were designed to transport storm water to the Thames, the largest river in London and the main drain for the city. The idea was to prevent flooding during heavy rains by providing a controlled means of water discharge.

It is important to note that when these first sewers were constructed, it was actually illegal to discharge sewage directly into them. The sewers were primarily for storm water and it wasn't until later that the system would be adapted to handle sewage more effectively.

From Cess Pits to Flush Toilets

Before the sewers were designed for sewage, human waste in London was managed in various ways. Households would typically use cess pits, which are essentially underground reservoirs where waste is collected. The liquid waste would slowly drain into the surrounding earth, while the solid waste was left to accumulate. This situation was starkly inefficient. The contents of these cess pits were often removed by nightsoil men, typically two to three times a year.

The introduction of the flushing loo (also known as a water closet) changed the game entirely. No longer could the traditional cess pit method keep up with the growing population. With the widespread adoption of flushing toilets, the previous system became impractical. It soon became clear that a more efficient and comprehensive sewage system was necessary.

The Innovation of Bazalgette's Sewers

The expansion and modernization of the sewer system in London came about thanks to Joseph Bazalgette. Known as the “father of the London sewer system,” Bazalgette designed the east-west sewers in the 1860s which would revolutionize not only London's sewage management but also the public health of the city. This new infrastructure collected waste from homes and businesses through an intricate network of pipes, transporting it all to the sewage treatment facilities along the Thames.

Bazalgette's plan was complex and ambitious. It involved the construction of 456 kilometers of sewers, 1,100 kilometers of pipes, and the creation of huge pump stations. The purpose was not just to manage storm water but to ensure that sewage was properly collected and safely treated.

Other Methods Before Bazalgette's Innovations

Before Bazalgette's ambitious project, there were simpler, albeit less effective, methods of waste removal. The use of 'honey wagons' was common. These were essentially carts that collected human waste from homes. This method, while functional in the short term, was not as efficient as the continuous flow system that Bazalgette's design provided.

Even earlier, before the advent of honey wagons, people simply threw their waste into the streets. This method, known for its unsanitary conditions, was a common practice until the invention of the water closet in the late 19th century by Thomas Crapper - one of the most well-known names in bathroom fixtures. With Crapper's invention, the only thing needed was a system of pipes to carry the waste from homes to the rivers.

Conclusion

London's sewer system, originally designed for flood control, evolved to become one of the most comprehensive sewage management systems in the world. Through the innovations of Joseph Bazalgette and the technological advancements of the 19th century, the system was transformed to meet the needs of a rapidly growing and modernizing city. The evolution of the London sewer system is a testament to the significant impact of urban engineering on public health and sanitation.