This paper offers an analysis of proximities between local public authorities and industrial actors in an urban industrial space through the lens of two networks : public transportation and water systems. We analyze “physical” (spatial) and “institutional” (compartmentalization, exchanges, cooperation) proximities, through the historical trajectory of the agglomeration of Roussillon, located in the mid-Rhône valley, and shaped by the establishment of the company Rhône-Poulenc (a major French chemical group) in the area at the beginning of the 20th century. We underline how a historical understanding of the links between local public authorities and industrial actors allows comprehension of the existence, emergence and disappearance of these links. The paper then questions the mutual roles of local public authorities and industries in territorial development. After a description of a “disengagement” of the private firm in the second half of the 20th century, we introduce the “industrial and territorial ecology” approach as an opportunity for “re-engagement” of private firms in the area through increased cooperation with local public authorities.