As the city grew, it became bounded by the Humber River to the west and the Don River to the east. Several smaller rivers and creeks in the downtown area were routed into culverts and sewers and the land filled in above them, including both Garrison Creek and Taddle Creek, the latter running through the University of Toronto. Much of Castle Frank Brook became covered during this time. At the time, they were being used as open sewers and were becoming a serious health problem. The re-configuration of the Don River mouth to make a ship channel and lakeshore reclamation project occurred in the 1880s, again largely driven by sanitary concerns and establishing effective port commerce.