The covering of the Senne (; ) was the covering and later diverting of the main river of Brussels, Belgium, and the construction of public buildings and major boulevards in its place. Carried out between 1867 and 1871, it is one of the defining events in the history of Brussels.
The Senne/Zenne (French/Dutch) was historically the main waterway of Brussels, but it became more polluted and less navigable as the city grew. By the second half of the 19th century, it had become a serious health hazard and was filled with garbage and decaying organic matter. It was heavily polluted, and it flooded frequently, inundating the lower town and the working class neighbourhoods that surrounded it.
Numerous proposals were made to remedy this problem, and in 1865, the City of Brussels' mayor, Jules Anspach, selected a design by the architect Léon Suys to cover the river and build a series of grand central boulevards and public buildings. The project faced fierce opposition and controversy, mostly due to its cost and the need for expropriation and demolition of working-class neighbourhoods. The construction was contracted to a British company, but control was returned to the government following an embezzlement scandal. This delayed the project, but it was still completed in 1871. Its completion allowed the construction of the modern buildings and boulevards that are focal to downtown Brussels today.
In the 1930s, plans were made to cover the Senne along its entire course within the greater Brussels area, which had grown significantly since the 19th-century covering. By 1955, the course of the Senne was diverted to the downtown's peripheral boulevards. In 1976, the disused tunnels were converted into the North–South Axis of Brussels' underground tram system, the premetro. Actual purification of the waste water from the Brussels-Capital Region was not completed until March 2007, when two treatment stations were built, thus finally cleansing the Senne after centuries of problems.
The Senne in Brussels
At the beginning of the 19th century, Brussels was still in many ways a medieval city. The Royal Quarter in the historic upper town, inhabited mainly by the nobility and the richer members of the bourgeoisie, was upscale and modern. The rest of the city, however, in particular the lower town, located in the western half of the Pentagon, in the valley of the Senne river, was densely populated and industrial, characterised by an illogical street layout, back alleys, narrow streets, and numerous dead-ends.
The Senne split into two branches in Anderlecht, penetrating the Pentagon, the former site of the second city walls, in two places. The main and more southern arm entered through the Greater Sluice Gate, near today's Brussels-South railway station. The smaller northerly arm entered through the Lesser Sluice Gate, near today's Ninove Gate. The courses of the two traced a meandering path through the city centre, forming several islands, the largest of which was known as Saint-Géry/Sint-Goriks Island. The two branches met up on the north side of Saint-Géry Island, exiting the Pentagon one block east of the Antwerp Gate. A man-made arm, called the "Lesser Senne" (, ), continued on the borders of the Pentagon in the former moat, outside the sluice gates. It followed the Brussels–Charleroi Canal before rejoining the main part of the Senne north of the city.
Still described, in the 18th century, as a river with a "useful and pleasant course", the Senne had long since lost its usefulness as a navigable waterway, having been replaced by the first half of the 19th century by the Brussels–Charleroi Canal and the Brussels–Scheldt Maritime Canal (also known as the Willebroek Canal). The Senne had always been a river with an inconsistent flow, often overflowing its banks. In times of heavy rainfall, even the sluice gates were unable to regulate the flow of the river, which was often swollen by numerous creeks flowing down from higher ground. Making matters worse, within the city, the river's bed was narrowed by encroaching construction due to demographic pressure. The supports of numerous unregulated bridges impeded water flow and caused water levels to rise even further, exacerbated by a riverbed of accumulated waste.
During dry periods, however, much of the Senne's water was diverted for the needs of the city's populace, as well as to maintain the water level in the Charleroi Canal. This left a flow too feeble to evacuate the filthy water, leaving the sewage, garbage, detritus and industrial waste that had been dumped into the river to accumulate in the stagnant water. The Senne, which a witness in 1853 described as "the most nauseous little river in the world", had become an open-air sewer spreading pestilential odours throughout the city. Early in the second half of the 19th century, Brussels saw numerous dry periods, floods and a cholera epidemic, caused as much by the river itself as by the poverty and the lack of hygiene and potable water in the lower city. This forced the governments of the Province of Brabant and the City of Brussels to act.
Attempts at purification
The first studies and propositions to clean up the river date back to 1859, and between 1861 and 1864, the Brussels authorities assigned successive commissions of engineers to examine possible solutions. Dozens of different ideas were submitted, many of which were completely unfeasible. Several of them proposed diverting large amounts of cleaner water from other rivers upstream to dilute the Senne, while greatly improving the drainage system in the city. Other proposals involved diverting the Senne's main course completely to the Lesser Senne, which would then be enlarged and thus be more useful for boat traffic and mills. Others considered any sort of sanitisation impossible, and proposed covering the Senne without greatly changing its course. Among these was a proposal to double the size of the underground drainage tunnels, creating space for a subterranean railroad tunnel. The idea was ahead of its time, and would be implemented a century later with the North–South connection.
In 1865, King Leopold II, speaking to the City of Brussels' then-mayor, Jules Anspach, expressed the wish that Brussels "will succeed in getting rid of this cesspool called the Senne" before the end of his reign. In October of that year, the municipal council adopted a project submitted by the architect Léon Suys, which had Anspach's backing. The plan involved suppressing the Senne's secondary arm by closing the Lesser Sluice Gate and rectifying the sinuous course of its main arm between Brussels-South railway station and the north of the city. This main branch would be channelled into tunnels, to be placed directly beneath a long, straight boulevard, stretching from the Greater Sluice Gate to the Temple of the Augustinians (now the Place de Brouckère/De Brouckèreplein) before splitting into two. One branch was to head towards Brussels-North railway station and the present-day Place Charles Rogier/Karel Rogierplein, the other towards the Antwerp Gate, thus forming a long, narrow "Y" shape.Map of Suys' proposal. City Archives of Brussels: p.p. 1.169
Anspach's backing of Suys' proposal was a calculated decision, as he had radical plans to transform the city. Anspach saw the proposal as an unexpected boon, as it allowed him to accomplish several of his goals at once. It had long been his ambition to transform the impoverished lower city into a centre of business and commerce, suitable for a modern capital (Belgium had declared its independence in 1830, with Brussels its capital). He wanted to attract the middle class, most of whom had left the dingy downtown for the cleaner suburbs, including the Leopold Quarter (now often called the European Quarter) and the Avenue Louise/Louizalaan, causing a large loss in tax revenue for the city. The elimination of the numerous alleys and dead-ends in the lower town in favour of a large, straight, wide, open-air boulevard, linking the two rapidly growing train stations, seemed both a necessity and an opportunity to beautify the city and improve both traffic circulation and hygiene.
Controversy and opposition
The Belgian Parliament had passed a law in 1858 allowing the expropriation of privately owned land by the government when the land was to be used for the "greater good". This could be done even if the project was still speculative in nature, and allowed for more land to be taken beyond what was strictly necessary for a project. The city expropriated large swathes of the lower town, counting on reselling the land for a profit, which, after the project was complete, would be on a grandiose modern boulevard in an upper-class neighbourhood. The selling of land after the project's completion was seen as a way of financing the project itself. That the lower town's poorer residents were forced away into other already overcrowded districts or into the surrounding suburbs did not trouble the upper classes very much, as the displaced residents did not pay taxes or have the right to vote.
Even after Suys' proposal was officially adopted in 1865, Anspach faced strong opposition to the project. This opposition came first from engineers who felt that the covering was incompatible with Brussels' geology, would accumulate potentially dangerous gases and would not be able to handle enough water to prevent floods. Others opposed to the project complained about the soaring taxes resulting from its high cost, poor compensation for seized property and the lack of public input into the project. The press accused Anspach of being responsible for demolishing Brussels' old town, and published numerous caricatures mocking him.
A liberal, Anspach feared the government's weakness and rigidity and therefore gave the work of covering the river to a private British company, the Belgian Public Work Company (the English name was used), which was created for the task. The contract was signed on 15 June 1866, and the contractor was given three years for the undertaking. However, partway through construction, it was forced to relinquish control to the City of Brussels after an embezzlement scandal in which a company director, Frédéric Doulton, allegedly attempted to steal 2.5 million Belgian francs from the company. Anspach only barely kept his office in the 1869 by-elections.
Demolition and construction
The covering of the river itself, by far the largest operation, absorbed two-thirds of the subsidies granted by the public authorities—the Belgian state, the Province of Brabant and the City of Brussels—amounting to 18 million Belgian francs. The city's financial resources for public works were temporarily monopolised by the operation. Now in sole control of the works, the city had to rely on the sub-contractors working on the project to see it through to completion.
The expropriation procedure of the first 1,100 houses located on the route was long and laborious, requiring an individual assessment of each building. The gigantic work, involving thousands of workers, began on 13 February 1867. From 1867 to 1871, the river was temporarily diverted and much of the old city centre was opened up. To prevent the water from rising with each shovel stroke, wells had to be installed at regular intervals, then the water pumped out to lower the water table below the apron. Excluding the important sewers built upriver and downriver in the adjacent suburbs, the covered section itself was in length. Constructed from bricks, the covering consisted of two parallel tunnels, and a set of two lateral drainage pipes, each taking in waste water from its respective side of the street.