ILLINOIS RESERVOIR REPORT

Last Updated: December 28, 2025

In Illinois, several dams and reservoirs are currently experiencing lower than average storage levels for the time of year, as evidenced by recent gage height measurements. Notably, Channel Lake near Antioch, Fox Lake near Lake Villa, and Nippersink Lake at Fox Lake all show significant decreases in gage height compared to their respective averages. As of December 28, 2025, Channel Lake's gage height was recorded at 2 feet, a notable decline from its average of 4.15 feet. Similarly, Fox Lake and Nippersink Lake both recorded gage heights of 2 feet, down from their averages of 3.91 and 3.85 feet, respectively. These low levels could indicate potential issues with water supply, recreation, and ecological impacts for the surrounding areas if the trend continues.

Upon cross-referencing with multiple data sources, including local hydrological surveys and historical records, these abnormal conditions at the Illinois dams and reservoirs appear to be outside the norm for this season. Typically, the water levels in winter are influenced by factors such as snowpack accumulation and subsequent meltwater, as well as precipitation patterns and river flows. However, the lack of significant snowfall or possible lower-than-average river inflow could be contributing factors to the reduced water storage observed. The implications of these low gage readings may extend beyond immediate water storage concerns, potentially affecting water management decisions, agricultural irrigation needs, and local ecosystems reliant on stable water levels. It is crucial for both water resource managers and the public to monitor these conditions closely and consider adaptive strategies to address the potential long-term effects of these observed abnormalities.

Illinois has several reservoirs and dams, primarily used for flood control, municipal water supply, and recreational activities. Major reservoirs in the state include Lake Shelbyville, Lake Springfield, Lake Decatur, and Rend Lake. These reservoirs receive water from various streams and rivers, including the Kaskaskia River, Sangamon River, and the Little Wabash River. Snowpack and mountains are not significant factors in Illinois hydrology, as the state has a relatively flat landscape. However, seasonal trends can affect water levels, with higher precipitation in the spring and lower levels in the summer. Drought conditions can also impact reservoir levels, with Lake Shelbyville experiencing record low levels in 2012 due to a severe drought. Overall, Illinois' reservoirs and dams play a critical role in managing water resources for the state's population and economy.

Illinois has several reservoirs and dams, primarily used for flood control, municipal water supply, and recreational activities. Major reservoirs in the state include Lake Shelbyville, Lake Springfield, Lake Decatur, and Rend Lake. These reservoirs receive water from various streams and rivers, including the Kaskaskia River, Sangamon River, and the Little Wabash River. Snowpack and mountains are not significant factors in Illinois hydrology, as the state has a relatively flat landscape. However, seasonal trends can affect water levels, with higher precipitation in the spring and lower levels in the summer. Drought conditions can also impact reservoir levels, with Lake Shelbyville experiencing record low levels in 2012 due to a severe drought. Overall, Illinois' reservoirs and dams play a critical role in managing water resources for the state's population and economy.