The restoration of ecological continuity in Thérain (Seine-Normandy catchment area) by 2015 was ordered in December 2012 by the departmental authorities. The Montataire dam in Thérain, operated by the company ArcelorMittal, was considered as an impediment to the ecological continuity.


o Hydrological studies
o Hydraulic modelling of the Thérain catchment area to determine the flow rates and their impact on the Oise River navigation
o Hydrogeological and hydromorphological analysis
o Environmental expertize (sub-consultant: Hydrosphère)
o Technical and economic feasibility study of each restoration scenario
o Analysis of the morphological constraints and adaptation of the proposed measures


ArcelorMittal Atlantique and Lorraine region authorities

Key figures

Period of services

June 2015 - October 2015

Key challenges