The Wasatch County Health Department confirmed algae found in the water at Deer Creek Reservoir could make people and animals sick.
The situation at the Charleston day-use area is more serious where an algal bloom is visible.
Visitors are not allowed to swim, jet or water ski, wade into the water or bring animals. The health department recommends boaters avoid algal blooms and advises anglers to thoroughly clean their fish.
The health department says people should not drink water from the reservoir.
Signs of the toxic algae have other areas of Deer Creek Reservoir under a health watch like Wallsburg where there are algae mats.
Harmful algal blooms usually occur in standing water. Their appearances can vary widely. According to the Utah Department of Water Quality, blooms are often various shades of green or blue, but may also be red, pink, white, gray or purple. The texture of blooms may resemble spilled paint, green globules, surface scum, foam, floating mats or grass clippings.
Some algal blooms rise and fall in the water and may not be visible on the surface.
