EDMOND, Oklahoma - As forecasters predict more flooding in the coming days, campgrounds and lakes across the state of Oklahoma have begun to close as fears of dangerous debris and contamination grow just ahead of Memorial Day weekend.

As always there's a concern of animals like snakes or insects that can swim into floodwaters beyond where they normally are. Oklahoma is home to six different species of water snakes. Only one, the cottonmouth or water moccasin is venomous.

Insects and spiders also use standing or pooled water in trash or debris as havens to build nests or webs. Biting insects, particularly mosquitoes are disease carriers including West Nile virus.

The spread of disease from debris and run off also spikes after flooding and that's what has health officials worried. According to the Centers for Disease Control, heavy rains pull chemicals and contaminants from surrounding areas. Those chemicals can be industrial or household waste. They also include human and animal waste. Biological and hazardous waste can cause minor symptoms like skin or eye irritation to gastrointestinal problems to tetanus. 

Coal ash from campsites can also contain carcinogens, according to the CDC, including mercury, arsenic and chromium. Prolonged exposure to those chemicals is known to cause cancer.

Public health officials recommend washing with soap and water before and after getting out of lake water and avoiding going to areas littered with debris. Ultimately, they say the best way to stay safe, is to stay dry.

“There’s a lot of things when you get a flooded lake when the waters come up, there are a lot of things that you can’t see that you don’t know are there,” Edmond spokesperson Casey Moore said Tuesday after the city closed Arcadia Lake indefinitely.

The concern over disease and debris come just before one of the busiest water-going weekends of the year. Many campsites around Grand Lake, Lake Tenkiller and Gibson Lake have already been closed by the State Tourism Department.

Lake Thunderbird in Norman also saw considerable flooding Tuesday. Officials recommend checking lake or park websites before visits over the holiday weekend.