Urban metabolism and river systems: an historical perspective – Paris and the Seine, 1790–1970

Abstract

Abstract. The aim of this paper is to analyse interaction between Paris and the Seine during the industrial era, 1790–1970, a period marked by strong population growth, changes in techniques, and the absence of specific legislation on environmental issues. The viewpoint focuses on exchanges of waters and wastes between city and river, quantifying them and tracing evolution in the light of the strategies implemented by the stakeholders in charge. The study combines industrial ecology, local history and the history of technology. From 1790 to 1850, waste matters, and especially excreta, were considered as raw materials, not refuse: they generated real profits. The removal of human excreta aimed not only at improving urban hygiene, but at producing the fertilizers needed in rural areas. Discharging them into the river was out of the question. But after the 1860s, several factors upset this exploitation, notably domestic water supply. Even so, Parisian engineers continued to process sewage using techniques that would not only ensure hygiene but also conciliate economic and agricultural interests. Both of these early periods are thus noteworthy for a relative limitation of the river's deterioration by urban wastes. Not until the 1920s, when domestic water supply had become the rule and excreta came to be considered as worthless waste, was the principle of valorisation abandoned. This led to important and long-lasting pollution of the Seine, aggravating the industrial pollution that had been in evidence since the 1840s. Analysing the priorities that led to the adoption of one principle or another in matters of urban hygiene and techniques, with the causes and consequences of such changes, enables us to understand the complex relations between Paris and the Seine. From raw material to waste matter, from river to drain, the concept of quality in environment remains the underlying theme.