On his arrival in Belgium, a French outcast wrote: "The Senne, recalling in name only the great river of Paris, is a trickle of muddy water: it will only manage to enhance the beauty of the city if it is buried beneath the famous boulevard of which the new king laid the foundation stone in fastuous ceremony."
Boulevards de la Senne starts by naming in writing the elements that make up the film. In white letters on a black background: “The voices of Saidou Ly, Joan-Noël Boissé, Juliette Achard, Ian Menoyot and Ryszard Karcz. Also, a poem by Saidou Ly that is part of Des intégrations, the book La Senne by Gustave Abeels (1983), the book La Belgique by Camille Lemonnier (1888), photographs from the Brussels Archive (1860-1866) and a song: Trois Chant Sacrés pour soprano et trio à cordes (1951)”. By combining all these things, the film-makers create an essay film that talks about Brussels and the development work that made a permanent mark on the city's experience: covering over the river Senne in the mid-19th century. The film-makers use different devices to bring the Senne back, in a way, to flow through the Belgian capital once more. The film begins with a map, that gives way to images shot in the streets today. Views of different places, the past of which is explained by different voiceovers that recount the history of the place: the pollution of the river, the dirty water, the work to cover it over and the compulsory purchases involved in this. In the final part of the film, the past moves from the voiceover to the pictures: various archive photographs show us what Brussels was like before the Senne was covered over. A city where the streets were flooded with water.