Even though all major cities in southwestern British Columbia are located west of the Garibaldi chain, future eruptions from Mount Garibaldi are expected to have significant impacts on the adjacent townships of Squamish and Whistler. An eruption column released during Peléan activity would discharge large amounts of tephra that would endanger aircraft. Tephra may also melt the large sheets of glacial ice east of Garibaldi and cause floods. This could later endanger water supplies from Pitt Lake and fisheries on the Pitt River. An explosive eruption and the associated tephra may also create temporary or longer-term water supply difficulties for Vancouver and most of southern British Columbia. The water reservoir for the Greater Vancouver drainage area is south of Mount Garibaldi.