Once so thick with algae that the water looked more like green paint than water, southwest Iowa’s Viking Lake has been on the up and up since a major watershed improvement there wrapped up in 2009.Five years of monitoring Viking Lake in southwest Iowa reveals the lake is clean enough to be removed from the list of Iowa impaired waters for algae growth.
Viking Lake’s watershed improvement projects included 32 engineered structures that trap sediment and nutrients to keep them from reaching the lake, as well as wetlands, terraces, septic system upgrades and fencing cattle out of streams. These efforts reduced sediment reaching the lake by 90 percent, and nitrogen and phosphorus levels in the lake dropped by 67 percent and 53 percent respectively, reducing algae problems.
Along with a 5.5-mile hiking area that encircles the lake, and a massive in-lake renovation that included adding rip-rap to strengthen the shoreline, fishing jetties and fish habitat, Viking is a whole new lake. And that shows, in people using the centerpiece of Viking Lake State Park, the improved fishing and in the numbers when it comes to water quality data.
“Water quality continues to improve at Viking Lake, thanks to the in-lake and watershed restoration efforts,” says Michelle Balmer, DNR Lake Monitoring Coordinator. “Viking Lake was on Iowa’s impaired waters list for both algae growth and for E. coli. From 2010 to 2014, water clarity improved 22 percent. The median for blue-green algae in the lake between 2010 and 2014 dropped 60 percent.”
In 2016, the EPA will review Iowa’s 2013-2014 Integrated Report, at which time, the DNR will find out if Viking Lake’s listing on the impaired waters list for algae growth can be formally removed. The EPA requires that two consecutive reports with no violations occur before the lake can be de-listed for a particular pollutant.
“The lake has also improved for bacteria,” adds Balmer. “Records for 2013 and 2014 look good, which is promising that Viking Lake may be removed from the impaired waters list for E. coli in 2018, if 2015 and 2016 continue without bacteria violations.”
Viking Lake is again providing good fishing for the angling public. “It is a favorite destination for small bass clubs hosting tournaments,” says Bryan Hayes, fisheries biologist for the DNR. “This is because of the high catch rates for bass. And, when you see folks in lawn chairs holding fishing rods at nearly every access point around the lake, you know that the catfishing is good.”
Once known for standout crappie fishing, the lake has returned to its former glory. “This last spring was excellent crappie fishing,” continues Hayes. “The size of bluegills has steadily increased since the renovation to the point that they will soon become an early summer attraction.”
Read more about Viking Lake and other water quality successes in Working For Clean Water, the DNR's annual watershed success story publication.