Impacts of climate change on the Chicago River system

Climate Change in Chicago By the end of the 21st Century, temperatures in Chicago are projected to rise 7-13 o F in winter and 9-18 o F in summer. Increasingly Variable Precipitation Seasonal precipitation is likely to change, increasing in winter by 10–25% and decreasing in summer by 5–20%. River levels will be lower, with severe flooding 50% higher than today’s levels when it does rain.

Temperature changes Overall, extreme heat will be more common and the growing season could be 3–6 weeks longer. Of even greater concern is the projected increase in extreme heat days (exceeding 97°F). By 2080– 2100, Illinois could see more than 25 such days annually, which will require improved warning systems and preparation to avoid severe health impacts.

Potential Impacts of a Hotter and Wetter Winter More Flooding More Erosion Extreme Runoff Invasive Pests Saturated Soils Increased Property Damage Repair & Recovery From Flooding Beach Closings Human Health Impacts Crop Loss & Decreased Soil Fertility

More Flooding Storms, and flooding in particular, will require changes in infrastructure. Municipalities in Illinois will have to upgrade water-related infrastructure including levees, sewer pipes, and wastewater treatment plants in anticipation of more frequent extreme downpours. Increased soil erosion and runoff of agricultural wastes are likely if the frequency of flooding increases, raising farmers’ costs to maintain soil fertility.

Potential Impacts of a Hotter and Drier Summer Frequent Drought Decreased Soil Moisture Less Aquatic Habitat Lower River & Lake Levels Increased CSO & Non-Point Source Pollution Crop Vulnerability Decline of Native Species Water Conflicts Infrastructure Changes Loss of Biodiversity Loss of Groundwater

Frequent Drought and Decreased Soil Moisture Development and climate change will degrade the natural flood-absorbing capacities of wetlands and floodplains, resulting in increased erosion and additional water pollution from nutrients, pesticides, and other contaminants. More frequent extreme weather events such as storms and floods, exacerbated by stream channeling and more paved surfaces, result in greater influx of sewage during combined sewer overflows and general non-point source pollution.

Chicago River Lower river levels Drought & decreased aquatic habitat Increased severe flooding CSO & non-point source pollution Loss of Biodiversity Native species decline & Non-native species increase

Turf grass Why are native plants important? Infiltration of storm water runoff Deep, fibrous roots that bind soil and prevent erosion Uptake of of excess nutrients that pollute the river, like phosphorus and nitrogen

Become a Chicago River Eco-Warrior Chicago River Eco-Warriors pledge to commit between five and five hundred hours dedicated to protecting and restoring the Chicago River watershed over the course of a year. Eco-Warriors do everything from volunteer at Friends’ events, attend restoration workdays, go to outreach events, and much more. Sign the pledge today!