ðɪ ˈɛlæsˈɑːmpʃən ɹˈɪvɚ wˈɔːɾɚʃˌɛd ˌoʊvɚlˈæps tˈuː nˈætʃɚɹəl ɛnvˈaɪɹənmənts, ðə lɔːɹˈɛnʃən mˈaʊntɪnz ænd ðə səntlˈɔːɹəns lˈoʊləndz, wˌɪtʃ kˈʌvɚɹ ɐbˌaʊt ɐ θˈɜːd ʌvðə wˈɔːɾɚʃˌɛd ˈɛɹiə.
The L'Assomption River watershed overlaps two natural environments, the Laurentian Mountains and the St-Lawrence lowlands, which cover about a third of the watershed area.