RICHMOND, Va. (WRIC) — The Virginia Department of Health has announced a water advisory for several sections of Lake Anna after unsafe levels of harmful algae bloom was found in the upper and middle sections.

According to the VDH, the harmful algae bloom was found in the North Anna and Upper Pamunkey branches, including Terry’s Run, of Lake Anna in Orange, Louisa and Spotsylvania counties. While algae is a normal part of fresh and saltwater ecosystems, an above-average amount of algae cells gathered together is called a “bloom,” and has the potential to be harmful to humans and animals. Algae is prone to reproducing more rapidly in the warm spring and hot summer months.

The public is advised to avoid contact with specific areas of the lake until algae concentrations return to acceptable levels. The VDH said the harmful algae, called cyanobacteria, can cause skin rash and gastrointestinal illnesses, such as upset stomach, nausea, vomiting and diarrhea. Cyanobacteria blooms are more often green or blue-green in color, but can sometimes be red or brown.

The VDH recommends that all swimming, fishing, or letting children or pets play in the affected bodies of water should be avoided while the cyanobacteria bloom is at unsafe levels. If the water smells bad, looks discolored, or has foam, scum or algal mats on the surface, the VDH says to stay out of the potentially harmful bloom-affected water.

Affected areas:

Pamunkey Branch – Upper (including Terry’s Run) and Middle  

  • Upper – From the upper inundated waters of the Pamunkey to the confluence with Terry’s Run
  • Terrys Run – from the upper inundated waters of Terry’s Run to the confluence with the Pamunkey Branch
  • Middle – From the confluence of Terry’s Run with Pamunkey Branch to Rt. 612 (Stubbs Bridge)

North Anna Branch – Upper and Middle

  • Upper – From the upper inundated waters to the Rt. 522 Bridge.
  • Middle – From the Rt. 522 Bridge, to include Rt. 719 (Holladay Bridge), to Lumsden Flats at Rose Valley Dr.
The VDH said the harmful algae, called cyanobacteria, can cause skin rash and gastrointestinal illnesses, such as upset stomach, nausea, vomiting and diarrhea. The cyanobacteria blooms are more often green or blue-green in color, but can sometimes be red or brown. (Photo Courtesy of the Virginia Department of Health)

If you believe you may have been exposed to a harmful algae bloom, the VDH recommends contacting your healthcare provider.

A surveillance map of the bodies of water in Virginia that may be affected by harmful algae bloom is regularly updated on the Virginia Department of Health website and can be found here.