Big Break Regional Shoreline: toxic algae advisories
Big Break Regional Shoreline, Contra Costa County. See all Contra Costa County waters.
What the state's records say
Danger advisory, last posted Oct 9, 2026. No all-clear recorded.
6 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 Big Break Regional Shoreline
The state has an advisory on file for Big Break Regional Shoreline (Danger advisory), last posted Oct 9, 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.
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 |
|---|---|
| Boat launch | Danger advisory, last posted Oct 9, 2026. No all-clear recorded. |
| Big Break Regional Shoreline | Danger advisory, last posted Sep 7, 2022. No all-clear recorded. |
| Spot not described | Danger advisory, last posted Jul 10, 2021. No all-clear recorded. |
| Big Break Regional Shoreline - Kayak Launch Area | Caution advisory, last posted Dec 31, 2020. No all-clear recorded. |
| Big Break Regional Shoreline - Kayak Launch Area | Caution advisory, last posted Dec 5, 2019. No all-clear recorded. |
| Big Break Regional Shoreline - Kayak Launch Area | The state's latest record, from Dec 7, 2018, recommends no advisory. |
| Big Break Regional Shoreline - Kayak Launch Area | Caution advisory, last posted Oct 12, 2017. No all-clear recorded. |
| Spot not described | The state's latest record, from Dec 8, 2016, recommends no advisory. |
Advisory history
Every advisory record the state has published for Big Break Regional Shoreline, 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 9, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Oct 1, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Sep 25, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Sep 18, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Sep 11, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Aug 31, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Aug 31, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Aug 21, 2026 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Aug 14, 2026 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Jul 31, 2026 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Jul 10, 2026 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Jul 3, 2026 | Boat launch | None | Updates from routine monitoring program-organization |
| Jun 19, 2026 | Boat launch | None | Updates from routine monitoring program-organization |
| May 26, 2026 | Boat launch | None | Updates from routine monitoring program-organization |
| May 1, 2026 | Boat launch | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Apr 24, 2026 | Boat launch | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Mar 10, 2026 | Boat launch | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jan 21, 2026 | Boat launch | None | Updates from routine monitoring program-organization |
| Oct 6, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| Sep 5, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| Aug 28, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| Aug 22, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Aug 18, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Aug 7, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Jul 24, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Jul 11, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Jun 2, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Jun 2, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| May 23, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| May 23, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| May 9, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Apr 11, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Apr 4, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Mar 14, 2025 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Mar 7, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| Feb 27, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| Feb 21, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| Feb 6, 2025 | Boat launch | None | Updates from routine monitoring program-organization |
| Jan 31, 2025 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Jan 17, 2025 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Jan 13, 2025 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Jan 2, 2025 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Dec 12, 2024 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Dec 5, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Dec 2, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Oct 31, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Oct 25, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Oct 17, 2024 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Oct 11, 2024 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Oct 4, 2024 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Sep 27, 2024 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Sep 20, 2024 | Boat launch | Caution | Updates from routine monitoring program-organization |
| Sep 13, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Aug 23, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Aug 15, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Aug 1, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Jul 26, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Jul 26, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Jul 22, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Jun 21, 2024 | Boat launch | Danger | Updates from routine monitoring program-organization |
| Jun 21, 2024 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Jun 14, 2024 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| May 24, 2024 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| May 10, 2024 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| May 3, 2024 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Apr 12, 2024 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Feb 19, 2024 | Boat launch | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Oct 5, 2023 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Sep 22, 2023 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Aug 25, 2023 | Boat launch | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Jul 28, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| Jul 28, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| Jul 6, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| Jun 28, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| May 10, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| Apr 28, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| Apr 5, 2023 | Boat launch | None | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Mar 29, 2023 | Boat launch | None | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Feb 3, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| Jan 27, 2023 | Boat launch | None | Updates from routine monitoring program-organization |
| Sep 7, 2022 | Big Break Regional Shoreline | Danger | Updates from routine monitoring program-organization |
| Sep 7, 2022 | Big Break Regional Shoreline | Warning | Updates from routine monitoring program-organization |
| Aug 31, 2022 | Big Break Regional Shoreline | Danger | Updates from routine monitoring program-organization |
| Aug 24, 2022 | Big Break Regional Shoreline | Danger | Updates from routine monitoring program-organization |
| Jul 10, 2021 | Spot not described | Danger | Advisory based on visual and toxins |
| Dec 31, 2020 | Big Break Regional Shoreline - Kayak Launch Area | Caution | Advisory based on visual and toxins |
| Dec 5, 2019 | Big Break Regional Shoreline - Kayak Launch Area | Caution | |
| Dec 7, 2018 | Big Break Regional Shoreline - Kayak Launch Area | None | |
| Oct 12, 2017 | Big Break Regional Shoreline - Kayak Launch Area | Caution | |
| Dec 8, 2016 | Spot not described | 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.