By Miriam Raftery

November 21, 2013 (San Diego) -- The County Department of Environmental Health has issued a warning for swimmers and surfers to avoid coastal waters for at least 72 hours after the rainstorms currently moving across the region.

Levels of bacteria in ocean waters and Mission Bay can rise to dangerous levels after a rainstorm due to urban runoff, especially near storm drains, creeks, rivers and lagoon outlets.