East Bay

Bird Sanctuary-Crown Beach (Alameda Co)

Inconclusive today.
Last sampled Apr 20, 2026 · 43 days ago

Last sample is over 30 days old — too stale to be a reliable swim-safety indicator.

Plate I: Location

Ninety days of readings.

Log scale · MPN/100mL

Each dot is one sample taken by the monitoring agency. The dashed brick line marks the EPA single-sample limit.

SafeCautionUnsafe

Common questions.

Is Bird Sanctuary-Crown Beach (Alameda Co) safe to swim today?
Bird Sanctuary-Crown Beach (Alameda Co) is currently inconclusive for swimming. Last sample is over 30 days old — too stale to be a reliable swim-safety indicator.
When was Bird Sanctuary-Crown Beach (Alameda Co) last tested?
The most recent water-quality sample at Bird Sanctuary-Crown Beach (Alameda Co) was collected on Apr 20, 2026 (43 days ago). California monitoring agencies test Bay Area beaches weekly during swim season (roughly May through October).
What is the bacteria level at Bird Sanctuary-Crown Beach (Alameda Co)?
The latest reading at Bird Sanctuary-Crown Beach (Alameda Co) shows 30-day enterococcus geomean at 11 MPN/100mL (EPA geomean limit: 35); and enterococcus at 6 MPN/100mL (EPA single-sample limit: 104).
Does rain affect water quality at Bird Sanctuary-Crown Beach (Alameda Co)?
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 Bird Sanctuary-Crown Beach (Alameda Co) located?
Bird Sanctuary-Crown Beach (Alameda Co) is located in the East Bay area of the San Francisco Bay region (coordinates: 37.7540°N, 122.2510°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 Bird Sanctuary-Crown Beach (Alameda Co) 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

For general guidance only · Conditions change · Swim at your own risk