The San Diego County Department of Environmental Health issued a General Rain Advisory on Tuesday directing swimmers, surfers and others to avoid water contact at all beaches and bays following recent rainfall. The agency said swimming, surfing and diving should be avoided during rain and for 72 hours following rainfall.

The agency said with rain comes urban runoff that may contain large amounts of bacteria from sources such as animal waste, soil and decomposing vegetation. This runoff can cause bacteria levels to rise in ocean and bay waters especially near storm drains, creeks, rivers and lagoon outlets, according to the department.