The City of Ottawa is referred to as the City of Two Rivers. Nearly 12,000 square miles of drainage meet where the Fox and Illinois Rivers unite in downtown Ottawa. Some of the highest recorded flooding events have occurred here during the past 10 years, and more will occur. To find out if your property is in a regulated floodplain or if there is historic flooding on your property, please contact the City at 815-433-0161 ext. 230.