The Services, Subject Of This Contract, Concern The Initial State And The Physico-Chemical And Biological Monitoring Of Watercourses And Thalwegs Which Are Impacted By The Work To Upgrade The Rn 141 To 2X2 Lanes Between Chasseneuil-Sur-Bonnieure And Roumazières-Loubert, As Well As The Hydromorphological Monitoring Of Bonnieure.