Lake Chabot: toxic algae advisories
Lake Chabot, Alameda County. See all Alameda County waters.
What the state's records say
Danger advisory, last posted Oct 16, 2026. No all-clear recorded.
8 reported spots here have an advisory with no all-clear recorded.
Reporting is voluntary, so the state may not have recorded an end even if conditions changed. Check posted signs and the official map.
What this level asks: Toxins may be at levels that can seriously harm people and animals. Stay out of the water and keep children and pets away from the water and the shore.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Lake Chabot
The state has an advisory on file for Lake Chabot (Danger advisory), last posted Oct 16, 2026, and no all-clear recorded. Keep your dog out of the water and away from scum on the shore until the state records an end.
Satellite estimate (not an advisory)
Week ending Sep 19, 2026: about 340,000 cells/mL of cyanobacteria near the center of Lake Chabot.
A satellite estimate from EPA CyAN for a 1.2 km² lake. It does not measure toxins and does not change the advisory status.
| Week ending | Estimate |
|---|---|
| Sep 19, 2026 | about 340,000 cells/mL |
| Sep 12, 2026 | about 730,000 cells/mL |
| Aug 29, 2026 | about 540,000 cells/mL |
| Jul 25, 2026 | about 480,000 cells/mL |
| Mar 28, 2026 | about 540,000 cells/mL |
| Mar 21, 2026 | about 420,000 cells/mL |
| Jan 3, 2026 | about 730,000 cells/mL |
| Nov 1, 2025 | about 400,000 cells/mL |
This is a satellite estimate from the U.S. EPA's Cyanobacteria Assessment Network, not an advisory. It estimates how much cyanobacteria is in the water near the lake's center, not whether toxins are present: a high number does not mean toxins, and a low one does not mean there are none. It covers lakes of about 1 square kilometer and larger, so small ponds, dog parks and most rivers are not covered, and clouds can hide a lake for weeks. It never changes the advisory status above.
Satellite estimates: U.S. EPA Cyanobacteria Assessment Network (CyAN), from Copernicus Sentinel-3 data. Provisional, research-level estimates; EPA does not endorse this site. Checked Oct 22, 2026.
Reported spots
The state records each report at a spot, such as a beach or a boat ramp. Each spot's latest deciding record:
| Spot | Status |
|---|---|
| lake-wide | Danger advisory, last posted Oct 16, 2026. No all-clear recorded. |
| Boat Launch in front of Lake Chabot Marina & Cafe | Danger advisory, last posted May 2, 2025. No all-clear recorded. |
| Lake Chabot | Caution advisory, last posted Feb 13, 2023. No all-clear recorded. |
| lake-wide | The state recorded an end date of Dec 31, 2022. |
| Lake Chabot | Caution advisory, last posted Jul 16, 2021. No all-clear recorded. |
| Lake Chabot (Alameda Co) | Caution advisory, last posted Dec 31, 2020. No all-clear recorded. |
| Lake Chabot (Alameda Co) | Caution advisory, last posted Oct 24, 2019. No all-clear recorded. |
| Lake Chabot (Alameda Co) | Caution advisory, last posted Dec 7, 2018. No all-clear recorded. |
| Lake Chabot (Alameda Co) | Caution advisory, last posted Jan 17, 2018. No all-clear recorded. |
| Lake Chabot (Alameda Co) | The state's latest record, from Dec 8, 2016, recommends no advisory. |
Advisory history
Every advisory record the state has published for Lake Chabot, newest first. "None" is the state's record that no advisory was recommended on that date. "NA" records do not change a status.
| Date | Spot | State's level | Notes |
|---|---|---|---|
| Oct 16, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 9, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 1, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 18, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 3, 2026 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 31, 2026 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 21, 2026 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 24, 2026 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 17, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 10, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 3, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 26, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 19, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 5, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 1, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 22, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 15, 2026 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 8, 2026 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 24, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 10, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 13, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 26, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 16, 2026 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 10, 2025 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 19, 2025 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 22, 2025 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 18, 2025 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 8, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 31, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 23, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 6, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 9, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 2, 2025 | Boat Launch in front of Lake Chabot Marina & Cafe | Danger | Updates from routine monitoring program-organization |
| May 2, 2025 | Boat Launch in front of Lake Chabot Marina & Cafe | Danger | Updates from routine monitoring program-organization |
| Apr 23, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 11, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 28, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 28, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 21, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 14, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Mar 7, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 28, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 21, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 14, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Feb 6, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 31, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 24, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 24, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 17, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 13, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jan 2, 2025 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 20, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 12, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 2, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 12, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 31, 2024 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 4, 2024 | lake-wide | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 27, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 30, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 2, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 22, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 3, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 21, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 4, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 28, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 28, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 24, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 7, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 1, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 24, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 10, 2024 | lake-wide | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Apr 2, 2024 | lake-wide | Danger | Updates from routine monitoring program-organization |
| Mar 27, 2024 | lake-wide | Danger | Updates from routine monitoring program-organization |
| Mar 19, 2024 | lake-wide | Danger | Updates from routine monitoring program-organization |
| Mar 11, 2024 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Mar 1, 2024 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jan 19, 2024 | lake-wide | Danger | Updates from routine monitoring program-organization |
| Aug 29, 2023 | lake-wide | Danger | |
| Aug 29, 2023 | lake-wide | Caution | |
| Aug 9, 2023 | lake-wide | Caution | |
| Jun 6, 2023 | lake-wide | Caution | |
| May 18, 2023 | lake-wide | Caution | |
| May 5, 2023 | lake-wide | Caution | |
| Apr 28, 2023 | lake-wide | Caution | |
| Feb 14, 2023 | lake-wide | Caution | |
| Feb 13, 2023 | Lake Chabot | Caution | Suspected illness reported; Under investigation |
| Jan 27, 2023 | lake-wide | Caution | |
| Dec 30, 2022 | lake-wide | Caution | |
| Oct 18, 2022 | lake-wide | Caution | End date recorded: Dec 31, 2022. Updates from routine monitoring program-organization |
| Oct 18, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Sep 15, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jul 28, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jul 21, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jul 8, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jul 1, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jun 10, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jun 2, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| May 18, 2022 | lake-wide | Caution | Updates from routine monitoring program-organization |
| Jul 16, 2021 | Lake Chabot | Caution | Advisory based on visual and toxins |
| Dec 31, 2020 | Lake Chabot (Alameda Co) | Caution | Advisory based on visual and toxins |
| Oct 24, 2019 | Lake Chabot (Alameda Co) | Caution | |
| Dec 7, 2018 | Lake Chabot (Alameda Co) | Caution | |
| Jan 17, 2018 | Lake Chabot (Alameda Co) | Caution | |
| Dec 8, 2016 | Lake Chabot (Alameda Co) | None |
Source
Advisory data: California State Water Resources Control Board, Freshwater Harmful Algal Bloom Program, via data.ca.gov (public domain). Advisories are recommendations; reporting is voluntary and incomplete. The state's data. An advisory ends only when the state records a later "None" (no advisory recommended) at the same spot, or an end date. A blank end date is unknown.