ONAWA – Blue Lake, located within Lewis and Clark State Park, continues to experience abnormally low water levels that may impact recreation opportunities. Launching boats is not recommended with the current low water levels.
Water levels in oxbow lakes adjacent to the Missouri River, including Blue Lake, are lower than normal due to dry conditions in western Iowa and historic low flows in the Missouri River.
The current drought period in Western Iowa began in 2020. Climate conditions over the last three years are some of the driest three-year periods in the 128-year record for the region. In the past two years, annual runoff was at least 25 percent below normal levels. Local average annual precipitation is also below normal for the area, contributing to the low water conditions at Blue Lake.
Blue Lake, like many other oxbow lakes, is characterized by a small watershed drainage area relative to the size of the lake and a localized water recharge area. Oxbow lakes form when a curve (or meander) in a river finds a shorter path, effectively isolating the old curve to form an oxbow lake in a low-lying plain near the side of the river. Water levels in these lakes are highly influenced by nearby river and groundwater levels.
The Iowa Department of Natural Resources (DNR) owns and maintains an auxiliary groundwater supply well, located approximately 1.25 miles northwest of Blue Lake. This well has been used in the past to maintain the water levels and maximize the recreational opportunities for the lake’s visitors during normal water years.
During drought conditions, the well is unable to provide sufficient water to maintain or increase water levels in the lake with the surrounding low water table and Missouri River water levels. Any water pumped into the lake would immediately be lost to the low groundwater table
DNR continues to monitor drought conditions and water levels at Blue Lake.