Hi  jmarchon, 

Thank you for reaching out to me. The data import introduced validation errors like role verification errors, water inside water and also incorrect alignment regarding waterway line feature. My team identified some JOSM Validation errors i.e role verification error for the way/1318572614, water inside water at 60.0289456, -73.5967396 and waterway line alignment at 60.121, -73.5478661, 60.1703084, -73.5109098, 60.072385, -73.6608228. I’ve fixed the errors. Kindly let me know if you have any further questions.