Ninety days of readings.
Log scale · MPN/100mLEach dot is one sample taken by the monitoring agency. Dashed lines mark each indicator's EPA single-sample limit; bars along the bottom show daily rainfall.
Enterococcus (limit 104)E. coli (limit 235)Fecal coliform (limit 400)Exceeds limitRainfall
Common questions.
- Is Doran Regional Park Beach safe to swim today?
- Doran Regional Park Beach is currently inconclusive for swimming. Last sample is over 30 days old — too stale to be a reliable swim-safety indicator.
- When was Doran Regional Park Beach last tested?
- The most recent water-quality sample at Doran Regional Park Beach was collected on Aug 17, 2026 (36 days ago). California monitoring agencies test Bay Area beaches weekly during swim season (roughly May through October).
- What is the bacteria level at Doran Regional Park Beach?
- The latest reading at Doran Regional Park Beach shows 30-day enterococcus geomean at 10 MPN/100mL (EPA geomean limit: 35); enterococcus at 10 MPN/100mL (EPA single-sample limit: 104); and E. coli at 10 MPN/100mL (EPA single-sample limit: 235).
- Does rain affect water quality at Doran Regional Park Beach?
- Yes. Heavy rainfall washes bacteria and pollutants from land into the water, raising contamination risk for 24–72 hours. The past 48 hours recorded 0.00 in of rain; the past 72 hours recorded 0.00 in. Our advisory threshold is ≥1.00 in over 48h (or ≥0.50 in over 72h) for enclosed or storm-drain beaches.
- Where is Doran Regional Park Beach located?
- Doran Regional Park Beach is located in the Marin area of the San Francisco Bay region (coordinates: 38.3134°N, 123.0430°W). You can get turn-by-turn directions via Google Maps or Apple Maps directly from this page.
- How is the water quality data for Doran Regional Park Beach collected?
- Bacteria samples are collected by California state and county health agencies under the AB 411 Safe-to-Swim program and reported to the state's Safe-to-Swim database (data.ca.gov). Rainfall figures come from Open-Meteo forecast and archive data. Bay Area Swim aggregates both sources and updates every morning.
Also nearby
Data: California Safe-to-Swim (ODbL 1.0) · Open-Meteo — Precipitation (CC-BY 4.0) · Pipeline status