IOWA RESERVOIR REPORT

Last Updated: February 21, 2026

In the State of Iowa, several key dams and reservoirs play a crucial role in water storage, flood control, and recreation. A recent analysis of the latest observations indicates that most reservoirs are maintaining gage heights close to their average levels. Clear Lake, Black Hawk Lake, Lake Panorama, and Spirit Lake are all reporting gage heights within a foot of their respective averages, suggesting that they are operating within expected parameters for this time of year. These measurements, taken last on February 21, 2026, reflect a stable hydrological condition in these bodies of water. West Okoboji Lake, however, is showing a gage height that is slightly below average, which could indicate lower water input or increased outflow.

Meanwhile, of particular interest is Corydon Lake, which is experiencing a streamflow rate significantly above its average (5 ft³/s current vs. 1.96 ft³/s average). This could be due to recent precipitation events, snowmelt, or other hydrological anomalies affecting the watershed. Conversely, Rathbun Lake is showing a minor decrease in gage height compared to its average, which could stem from decreased inflows or management actions. It's crucial to cross-reference these observations with multiple data sources to ensure accuracy, but such sources have not been provided. The observed deviations in conditions for West Okoboji Lake and Corydon Lake compared to their historical averages might be related to short-term weather patterns, long-term climatic changes, or watershed-specific factors such as land use changes or upstream water management practices. For stakeholders and residents, understanding the causes behind these abnormal conditions is essential for anticipating potential impacts on water resources, aquatic ecosystems, and regional water management strategies.

Iowa has several major reservoirs, including Coralville Lake, Rathbun Lake, and Saylorville Lake. These reservoirs are primarily fed by the Iowa River, Des Moines River, and Chariton River, respectively. Snowpack and mountains are not significant factors in Iowa's hydrology. Coralville Lake has experienced record high water levels in the past, with flooding in 2008 and 2013 causing significant damage. Drought conditions have also affected Iowa's reservoirs, with Saylorville Lake reaching record low levels in 2012. Seasonal trends in Iowa typically involve greater precipitation in the spring and summer months, leading to higher reservoir levels. However, prolonged periods of drought can disrupt this pattern. Overall, reservoirs and dams serve an important role in managing Iowa's water resources and mitigating the risk of floods and droughts.

Iowa has several major reservoirs, including Coralville Lake, Rathbun Lake, and Saylorville Lake. These reservoirs are primarily fed by the Iowa River, Des Moines River, and Chariton River, respectively. Snowpack and mountains are not significant factors in Iowa's hydrology. Coralville Lake has experienced record high water levels in the past, with flooding in 2008 and 2013 causing significant damage. Drought conditions have also affected Iowa's reservoirs, with Saylorville Lake reaching record low levels in 2012. Seasonal trends in Iowa typically involve greater precipitation in the spring and summer months, leading to higher reservoir levels. However, prolonged periods of drought can disrupt this pattern. Overall, reservoirs and dams serve an important role in managing Iowa's water resources and mitigating the risk of floods and droughts.