Dog Beach, O.B.: San Diego River outlet
Tested by San Diego County, usually every 5 days.
Taken yesterday.
Grade B over 11 tests from Oct 15, 2026 to Nov 12, 2026. 6 were over the limit.
Stay out until a retest passes
The latest test was over the safe limit. No one can say how long that lasts: the beach is cleared when a new test comes back under the limit. This site is usually tested every 5 days, so the next result should come around Tuesday, Nov 17.
County status: Advisory, checked Friday, Nov 13 (San Diego County Department of Environmental Health and Quality). The county’s posting is the final word.
Likely San Diego River runoff
This test site sits at the mouth of the San Diego River. The state lists the source here as unknown, but bacteria rise when the river carries runoff to the beach.
Enterococcus (DNA test) over time
- Thursday, Nov 12, 2026Enterococcus (DNA test) 2,190
- Friday, Nov 6, 2026Enterococcus (DNA test) 2,600
- Thursday, Nov 5, 2026Enterococcus (DNA test) 3,357
- Thursday, Oct 29, 2026Enterococcus (DNA test) 1,146
- Tuesday, Oct 27, 2026Fecal coliform under 2 · Total coliform 2 · Enterococcus 4
- Friday, Oct 23, 2026Enterococcus (DNA test) 1,7270.38 in of rain in the 3 days before
- Thursday, Oct 22, 2026Fecal coliform under 2 · Total coliform 14 · Enterococcus under 2 · Enterococcus (DNA test) 1,4950.23 in of rain in the 3 days before
- Wednesday, Oct 21, 2026Fecal coliform 4 · Total coliform under 20 · Enterococcus 2
- Tuesday, Oct 20, 2026Fecal coliform 4 · Total coliform 20 · Enterococcus 2
- Friday, Oct 16, 2026Enterococcus (DNA test) 1,104
Enterococcus and coliform bacteria live in the guts of people and animals. Health departments test for them because they travel with sewage, runoff and animal waste, so a high count is a warning that germs that do make people sick are likely in the water too. Clear water can still be contaminated: bacteria and viruses are too small to see.
San Diego County's DNA test (ddPCR) counts bacterial DNA instead of growing the bacteria in a lab, so it returns results the same day. Its numbers run higher than the older lab tests, which is why its safe limit is 1,413 rather than 104. The two are never compared on this page.
San Diego County's health department says swimming in water under an advisory can cause stomach illness, such as diarrhea and vomiting, and skin and ear infections. The EPA's national swimming guidelines are set at a level where about 32 to 36 of every 1,000 swimmers would get a stomach illness. A study of San Diego surfers found about 12 extra stomach-illness cases per 1,000 in wet weather, highest during rain and the day after, and back near normal 3 days later.
The grade is Nautical Nick's, built on the official limits: A is a quarter of the limit or less, B half or less, C under the limit, D over it, and F more than 10 times over. When a county posts an advisory or closes a beach, its sign is the final word.
Sources: California State Water Board beach test results; San Diego County Department of Environmental Health sample reports; Surfrider Foundation Blue Water Task Force; National Weather Service daily rain totals via the Iowa Environmental Mesonet (San Diego/Montgomery Fld, San Diego/Lindberg). Limits: California Code of Regulations, Title 17, Section 7958.