Ottawa River drainage basin
The Ottawa River drainage basin is the drainage basin in northern North America where surface water empties into the Ottawa River and adjoining waters. Spanning an area of about , it is the 12th largest drainage basin in Canada, occupying the Canadian provinces of Ontario and Quebec. It accounts for about 11% of the total Saint Lawrence River drainage area.
Fraser River
The Water Survey of Canada currently operates 17 gauge stations that measure discharge and water level along the majority of the mainstem from Red Pass just downstream of Moose Lake within the Mount Robson Provincial Park to Steveston in Vancouver at the river mouth. With an average flow at the mouth of about , the Fraser is the largest river by discharge flowing into the Pacific seaboard of Canada and the fifth largest in the country. The average flow is highly seasonal; summer discharge rates can be ten times larger than the flow during the winter.