East Bay

Berkeley Aquatic Park — South Lagoon

Inconclusive today.
Last sampled Mar 12, 2026 · 82 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

A newer sample on Mar 12 (7 days ago) reported a different analyte, so the chart's last point is older than the most recent reading. The current reading shown above reflects that newer sample.

Common questions.

Is Berkeley Aquatic Park — South Lagoon safe to swim today?
Berkeley Aquatic Park — South Lagoon is currently inconclusive for swimming. Last sample is over 30 days old — too stale to be a reliable swim-safety indicator.
When was Berkeley Aquatic Park — South Lagoon last tested?
The most recent water-quality sample at Berkeley Aquatic Park — South Lagoon was collected on Mar 12, 2026 (82 days ago). California monitoring agencies test Bay Area beaches weekly during swim season (roughly May through October).
Does rain affect water quality at Berkeley Aquatic Park — South Lagoon?
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 Berkeley Aquatic Park — South Lagoon located?
Berkeley Aquatic Park — South Lagoon is located in the East Bay area of the San Francisco Bay region (coordinates: 37.8497°N, 122.2974°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 Berkeley Aquatic Park — South Lagoon 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: City of Berkeley — Aquatic Park Water Quality (Public Domain) · Open-Meteo — Precipitation (CC-BY 4.0) · Pipeline status

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