CAMAS COUNTY, Idaho – A health advisory was issued Friday for Thorn Creek Reservoir in Camas, Gooding and Lincoln counties.

Public health officials said the advisory was issued due to harmful algal bloom (HAB).

This is the fourth health advisory issued for a reservoir in south-central Idaho. The other advisories were for Salmon Falls Creek Reservoir and Mormon Reservoir, both in July, and Magic Reservoir in early August.

All three previous advisories are ongoing, according to South Central Public Health District (SCPHD), one of the agencies that issued the advisory for Thorn Creek Reservoir. The other agency that has issued advisories is the Idaho Department of Environmental Quality (DEQ).

In a joint statement, the agencies said on Friday, “Results from recent DEQ water testing show the concentration of cyanobacteria (sometimes called blue-green algae) in the reservoir are now at unhealthy levels and have formed a harmful algal bloom.”

Public health officials advise people visiting any of the reservoirs with advisories to use caution and take the following steps to protect the health of themselves and their families and pets:

  • Avoid exposure to water in reservoirs under a HAB health advisory.
  • Do not drink water with a HAB advisory, as boiling and disinfecting doesn't remove toxins from water.
  • Do not allow pets to eat dried algae.
  • If you're fishing in HAB water, remove all fat, skin, and organs before cooking. Toxins are more likely to collect in those tissues. After handing the fish, be sure to wash your hands afterward.

HABs are not unusual in warm weather and typically shrink as water temperature drops, according to SCPHD.

“This is the fourth advisory in our region, but there are several more around the state,” SCPHD Public Health Program Manage Josh Jensen said. “These toxins can be damaging so we urge you to check any reservoir you want to recreate in before you, or your pets, enter the water.”