PIERCE COUNTY, Neb.-- A northeast Nebraska lake that has a history of having toxic algae in its water is still contaminated, officials say.

Willow Creek State Recreation Area gives families an opportunity to fish, boat, and camp, but it's still not a safe option for swimming in certain areas. Mike Sousek, general manager at the Lower Elkhorn Natural Resources District, said his office just got informed about a week ago about more toxic algae in parts of the lake.

"The sample last week came back positive for exceeding the recommended amount for toxic algae,” said Sousek. “That notice came on Thursday. We notified Game and Parks and they put up signs for people to stay out of the water.” 

You might be wondering why the blue-green algae keeps showing up in the lake. Sousek says it's a naturally reoccurring issue.

“It’s a seasonal thing,” Sousek said. “The algae needs sunlight and so now the days are longer. There’s just a lot of nutrients flowing into the Willow Creek.” 

The way the algae is developed is by two different things.

“We’ve done studies and we have a huge load of nitrogen coming in. We have a big load of phosphorus coming in,” said Sousek. “They combine there at the lake and they mix up and there’s so much nutrients for the algae to feast on and it just blooms and gets out of control.” 

Sousek said this type of algae is something you need to take seriously.

“It can be really irritating,” he said. “If you’re a small child or a dog, it could be toxic enough to kill you. It’s something you want to take seriously.”

The good news is swimming isn’t totally off-limits at the lake. Sousek says the algae is pretty easy to identify and you just want to steer clear of the areas it's in.

“It almost looks like a green paint on top of the water,” he added. “You definitely want to stay out of areas like that.”