Toxic algae is in dozens of lakes and streams around California, mostly in Northern California and health officials are issuing warning, even closing some lakes and waterways.

FOX's Jessica Rosenthal reports:

If you see the toxic algae in your favorite lake, river, or stream, it might be hard to miss:

(Abbs) "There's some pretty disgusting looking green stuff floating in a water body."

Bev Anderson Abbs is an environmental scientist with the Water Resources Control Board, she says warm conditions, stagnant water contribute to this and so is the now five-year drought:

(Abbs) "Water is not being released from the dams like normal so we're seeing slower moving water, in our rivers."

The toxins can be harmful, some people's pets have died. Some county officials are posting warning signs and others are closing lakes and reservoirs to people.

Jessica Rosenthal, FOX News.

Follow Jessica Rosenthal on Twitter: @JessicaFOXNews