DNR to host informational meeting about low levels in Blue Lake

Years of drought conditions on Iowa’s western edge have lowered water levels at Blue Lake and impacted recreation at the lake. 

The Iowa Department of Natural Resources is hosting a public meeting Thursday in Onawa to discuss the low water levels and the department’s ongoing studies and lake restoration projects at Blue Lake. 

200 years ago, when the Lewis and Clark expedition came through the region, the oxbow lake was an active channel of the Missouri River, but now it is fed by a small watershed off of the Missouri River, and is located in Lewis and Clark State Park just west of Onawa. 

According to DNR’s annual lake restoration report, Blue Lake has a number of “aesthetically objectionable conditions” like algal blooms, and low water clarity that contributed to decreased recreational use. 

 Since the early 2000s DNR has been working to restore the lake via chemical restoration, removal of “rough” fish and selective dredging. 

Water levels in the Missouri River have been “especially low” over the past five winters, which led to low groundwater levels in the region and impacted not only Blue Lake levels, but water in communities throughout western Iowa.

The lake is currently about five feet below its crest elevation, or the fullest pool of the lake. Ben Wallace, a fisheries biologist who has worked on Blue Lake’s restoration projects said drop means the lake has about one third of its full-pool volume. 

Wallace said the informational meeting Thursday will help address concerns within the community about the low lake levels and to explain DNR’s work at Blue Lake. 

“When we enter into these drought cycles, access gets tougher at these lakes, because the water starts to recede from the shoreline,” Wallace said. “And yeah, some lakes get hit harder than others with the drought.” 

According to the DNR report, the Lake Restoration Program spent about $10,000 on a dredging and fish barrier project at Blue Lake in the 2023-2024 fiscal year and allocated $265,000 in fiscal year 2025 for well and pump assessment, fish renovation and containment site improvements at the lake. 

Wallace said some folks in the community have questioned if the DNR’s dredging work contributed to the lake’s low levels, but he said lake restoration work is done very “systematically” with the “entire picture” in mind. 

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“We just don’t go into things blind,” Wallace said. “We get a pretty good understanding of things before we execute large scale construction projects like this.” 

Plus, Wallace said this isn’t the first time Blue Lake has had levels this low. He said historic maps of the region show levels just as low, if not lower in the 1930s. 

“All of these lakes that I’ve had throughout my district have gone through drought cycles about once every 10 to 12 years, and sometimes those droughts are more severe and they’re a little bit longer than other but in my experience, they all bounce back,” Wallace said. 

He said water levels in the lake are about on par with groundwater levels in the region. That type of drought takes more than just a good rain to replenish.

“Each year a successive drought just takes that much more to recharge the groundwater level,” Wallace said. “It’s going to have to be a return to average or above average precipitation levels for some time, because we’re not just talking about bringing up the lake — we’re talking about bringing up the water in the ground.”

Restoration work at the lake has also addressed turbidity, or water clarity, by eliminating and blocking common carp from the lake. 

Wallace said these bottom-feeding fish continually stir up the sediment on the bottom of the lake which causes cloudy water, poor conditions for other fish and makes it easier for algae to bloom on the surface. 

Wallace said common carp are a problem at a lot of lakes in Iowa, but high densities in Blue Lake have impacted the water quality. DNR’s lake restoration efforts included the installation of fish barriers and aggressive carp angling in the lake to help reduce the common carp populations. 

In addition to the work to restore the lake, Lewis and Clark State Park Manager Nathan Fylstra said his team has been working hard to improve the state park with updates to the visitor’s center, improved drainage systems and a general clean up of ditches and fences. 

“We’ve been changing a lot of stuff, revamping a lot of stuff,” Fylstra said. “It should look a lot better.” 

The park is adjacent to the 250-acre Blue Lake, which typically hosts summer swimmers, boaters and anglers. 

Wallace encouraged anyone with an interest in Blue Lake to attend the informational meeting Thursday at the Onawa Community Center, 320 10th Street, at 5:30 p.m. 

“Show up and ask questions,” Wallace said. “I am looking forward to the opportunity to demonstrate the lengths that we went to in studying this lake and this lake system.”