If you are planning a lake trip this holiday beware of blue-green algae.

While there are warnings for Eufaula Lake and Waurika Lake, it doesn't have to ruin your Memorial Day weekend. District officials say just look for posted signs.

Although, blue-green algae is naturally present in all lakes, warnings will be posted when the levels get too high.

The Army Corps of Engineers will post black and white signs if there is any risk, especially for children and pets.

Blue-green exposure can cause anything from nausea, to eye irritation and vomiting. The Corps says the best advice is when in doubt, stay out.