Discovery Bay: toxic algae advisories
Discovery Bay, Contra Costa County. See all Contra Costa County waters.
What the state's records say
Danger advisory, last posted Jul 8, 2026. No all-clear recorded.
34 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 Discovery Bay
The state has an advisory on file for Discovery Bay (Danger advisory), last posted Jul 8, 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 |
|---|---|
| Carillo Bay | Caution advisory, last posted Jul 8, 2026. No all-clear recorded. |
| Willow Lake | Caution advisory, last posted Jul 28, 2025. No all-clear recorded. |
| Kellogg Creek bridge at Newport Drive (544CCC014) | Caution advisory, last posted Sep 9, 2024. No all-clear recorded. |
| Lighthouse Place and Cypress Channel | Warning advisory, last posted Sep 9, 2024. No all-clear recorded. |
| Discovery Bay Yacht Club marina (544CCC005) | Danger advisory, last posted Sep 9, 2024. No all-clear recorded. |
| Seal Way near gas station and Cypress Channel | Caution advisory, last posted Sep 9, 2024. No all-clear recorded. |
| Willow Lake - Town Dock | Danger advisory, last posted Sep 9, 2024. No all-clear recorded. |
| Reef Court and Reef cove/Cypress Channel | Warning advisory, last posted Sep 9, 2024. No all-clear recorded. |
| Windward Point and driftwood bay | Caution advisory, last posted Jul 11, 2024. No all-clear recorded. |
| Lighthouse Bay | Visual observation, last posted Jul 10, 2024. No all-clear recorded. |
| Newport Lane and Kellogg Creek | Danger advisory, last posted Jul 8, 2024. No all-clear recorded. |
| Lighthouse Pl & Newport | Caution advisory, last posted Jul 5, 2024. No all-clear recorded. |
| Discovery bay Marina private NE area of town (544CCC022) | Caution advisory, last posted Jul 1, 2024. No all-clear recorded. |
| Orwood Old River Railroad inlet | Caution advisory, last posted Jun 28, 2024. No all-clear recorded. |
| Bolinas Place, Lighthouse Bay | Caution advisory, last posted Jun 28, 2024. No all-clear recorded. |
| Clipper Drive and Reef Court in Discovery Bay | Caution advisory, last posted Jun 12, 2024. No all-clear recorded. |
| Reef Ct cove | Reports on file, with no advisory level the state has classified. |
| Seal Bay, Discovery Bay Blvd | Caution advisory, last posted Jun 12, 2024. No all-clear recorded. |
| Driftwood Bay, near 4313 Monterey Court | Caution advisory, last posted Jun 7, 2024. No all-clear recorded. |
| numerous locations in Discovery Bay | Danger advisory, last posted Jul 27, 2022. No all-clear recorded. |
| cove in between driftwood and monterey | Caution advisory, last posted Oct 4, 2021. No all-clear recorded. |
| Yacht Club/Boardwalk Grill | Warning advisory, last posted Jul 8, 2021. No all-clear recorded. |
| near Clipper Dr. and Cypress Point | Caution advisory, last posted Jul 1, 2021. No all-clear recorded. |
| near Newport Drive and 4004 Capstan Place | Danger advisory, last posted Jul 1, 2021. No all-clear recorded. |
| Marina | Caution advisory, last posted May 7, 2021. No all-clear recorded. |
| Discovery Bay, at Beacon Bay | Caution advisory, last posted Jul 28, 2020. No all-clear recorded. |
| Discovery Bay, at Windward Bay | Caution advisory, last posted Jun 22, 2020. No all-clear recorded. |
| Discovery Bay, Starboard Bay | Caution advisory, last posted Jun 12, 2020. No all-clear recorded. |
| Discovery Bay, Cypress Channel | Danger advisory, last posted Jun 10, 2020. No all-clear recorded. |
| Discovery Bay, Reef Cove | Danger advisory, last posted Jun 10, 2020. No all-clear recorded. |
| Discovery Bay, at yacht harbor | Danger advisory, last posted Jun 10, 2020. No all-clear recorded. |
| Discovery Bay, Indian Bay | Caution advisory, last posted Jun 10, 2020. No all-clear recorded. |
| Discovery Bay, at Kellogg Creek | Reports on file, with no advisory level the state has classified. |
| Discovery Bay - E Dock at Yacht Harbor | Caution advisory, last posted Jul 8, 2019. No all-clear recorded. |
| Discovery Bay - Boardwalk Grill in Yacht Harbor | Caution advisory, last posted May 17, 2019. No all-clear recorded. |
| Discovery Bay, near Capstan Place | The state's latest record, from Dec 4, 2018, recommends no advisory. |
| Discovery Bay - Multiple Locations Within Entire Bay | The state's latest record, from Dec 4, 2018, recommends no advisory. |
| Driftwood Bay inside Discovery Bay | The state's latest record, from Dec 4, 2018, recommends no advisory. |
| Discovery Bay near Newport Drive | The state's latest record, from Nov 3, 2017, recommends no advisory. |
| Discovery Bay | Warning advisory, last posted Sep 9, 2016. No all-clear recorded. |
Advisory history
Every advisory record the state has published for Discovery Bay, 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 |
|---|---|---|---|
| Jul 8, 2026 | Carillo Bay | Caution | Visual monitoring only-present bloom |
| Jul 28, 2025 | Willow Lake | Caution | Lake-wide advisory |
| Sep 9, 2024 | Kellogg Creek bridge at Newport Drive (544CCC014) | Caution | Advisory based on visual and toxins |
| Sep 9, 2024 | Lighthouse Place and Cypress Channel | Warning | Advisory based on visual and toxins |
| Sep 9, 2024 | Discovery Bay Yacht Club marina (544CCC005) | Danger | Advisory based on visual and toxins |
| Sep 9, 2024 | Kellogg Creek bridge at Newport Drive (544CCC014) | Warning | Advisory based on visual and toxins |
| Sep 9, 2024 | Seal Way near gas station and Cypress Channel | Caution | Advisory based on visual and toxins |
| Sep 9, 2024 | Willow Lake - Town Dock | Danger | Advisory based on visual and toxins |
| Sep 9, 2024 | Reef Court and Reef cove/Cypress Channel | Warning | Advisory based on visual and toxins; Suspected illness reported |
| Aug 1, 2024 | Reef Court and Reef cove/Cypress Channel | Danger | Advisory based on visual and toxins; Suspected illness reported |
| Aug 1, 2024 | Willow Lake - Town Dock | Caution | Advisory based on visual and toxins |
| Aug 1, 2024 | Lighthouse Place and Cypress Channel | Danger | Advisory based on visual and toxins; Alert-high concentration toxins |
| Aug 1, 2024 | Reef Court and Reef cove/Cypress Channel | Danger | Advisory based on visual and toxins; Suspected illness reported |
| Aug 1, 2024 | Seal Way near gas station and Cypress Channel | Caution | Advisory based on visual and toxins |
| Aug 1, 2024 | Kellogg Creek bridge at Newport Drive (544CCC014) | Warning | Advisory based on visual and toxins; Alert-high concentration toxins |
| Aug 1, 2024 | Discovery Bay Yacht Club marina (544CCC005) | Caution | Advisory based on visual and toxins |
| Jul 11, 2024 | Windward Point and driftwood bay | Caution | Suspected bloom, investigation ongoing |
| Jul 11, 2024 | Windward Point and driftwood bay | Caution | Suspected bloom, investigation ongoing |
| Jul 10, 2024 | Lighthouse Bay | Visual observation | Visual monitoring only-present bloom |
| Jul 10, 2024 | Lighthouse Bay | Visual observation | Visual monitoring only-present bloom |
| Jul 8, 2024 | Discovery Bay Yacht Club marina (544CCC005) | Caution | Advisory based on visual and toxins |
| Jul 8, 2024 | Kellogg Creek bridge at Newport Drive (544CCC014) | Danger | Advisory based on visual and toxins; Alert-high concentration toxins |
| Jul 8, 2024 | Seal Way near gas station and Cypress Channel | Warning | Advisory based on visual and toxins |
| Jul 8, 2024 | Lighthouse Place and Cypress Channel | Danger | Advisory based on visual and toxins; Alert-high concentration toxins |
| Jul 8, 2024 | Newport Lane and Kellogg Creek | Danger | Advisory based on visual and toxins; Alert-high concentration toxins; Suspected illness reported |
| Jul 8, 2024 | Newport Lane and Kellogg Creek | Danger | Advisory based on visual and toxins; Alert-high concentration toxins; Suspected illness reported |
| Jul 5, 2024 | Lighthouse Pl & Newport | Caution | Suspected illness reported |
| Jul 5, 2024 | Lighthouse Pl & Newport | Caution | Suspected illness reported |
| Jul 1, 2024 | Reef Court and Reef cove/Cypress Channel | Caution | Advisory based on visual and toxins; Suspected illness reported |
| Jul 1, 2024 | Discovery bay Marina private NE area of town (544CCC022) | Caution | Lake-wide advisory |
| Jul 1, 2024 | Discovery Bay Yacht Club marina (544CCC005) | Caution | Lake-wide advisory |
| Jul 1, 2024 | Kellogg Creek bridge at Newport Drive (544CCC014) | Caution | Lake-wide advisory |
| Jul 1, 2024 | Seal Way near gas station and Cypress Channel | Caution | Lake-wide advisory |
| Jul 1, 2024 | Reef Court and Reef cove/Cypress Channel | Caution | Lake-wide advisory |
| Jul 1, 2024 | Newport Lane and Kellogg Creek | Caution | Lake-wide advisory |
| Jun 28, 2024 | Orwood Old River Railroad inlet | Caution | Suspected bloom, investigation ongoing |
| Jun 28, 2024 | Bolinas Place, Lighthouse Bay | Caution | Suspected bloom, investigation ongoing |
| Jun 28, 2024 | Orwood Old River Railroad inlet | Caution | Suspected bloom, investigation ongoing |
| Jun 28, 2024 | Bolinas Place, Lighthouse Bay | Caution | Suspected bloom, investigation ongoing |
| Jun 12, 2024 | Clipper Drive and Reef Court in Discovery Bay | Caution | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Reef Ct cove | NA - refer to Report Details | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Seal Bay, Discovery Bay Blvd | Caution | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Clipper Drive and Reef Court in Discovery Bay | Caution | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Reef Ct cove | NA - refer to Report Details | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Seal Bay, Discovery Bay Blvd | Caution | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Clipper Drive and Reef Court in Discovery Bay | Caution | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Reef Ct cove | NA - refer to Report Details | Suspected bloom, investigation ongoing; Under investigation |
| Jun 12, 2024 | Seal Bay, Discovery Bay Blvd | Caution | Suspected bloom, investigation ongoing; Visual monitoring only-present bloom |
| Jun 7, 2024 | Driftwood Bay, near 4313 Monterey Court | Caution | Floating/planktonic bloom observed; No cyano bloom w/photos |
| Jul 27, 2022 | numerous locations in Discovery Bay | Danger | Lake-wide advisory |
| Jun 15, 2022 | numerous locations in Discovery Bay | Danger | Lake-wide advisory |
| Jun 15, 2022 | numerous locations in Discovery Bay | Caution | Lake-wide advisory |
| Oct 4, 2021 | cove in between driftwood and monterey | Caution | visual monitoring based advisory |
| Jul 8, 2021 | Yacht Club/Boardwalk Grill | Warning | Advisory based on visual and toxins |
| Jul 1, 2021 | near Clipper Dr. and Cypress Point | Caution | Advisory based on visual and toxins |
| Jul 1, 2021 | near Newport Drive and 4004 Capstan Place | Danger | Advisory based on visual and toxins |
| May 7, 2021 | Marina | Caution | visual monitoring based advisory |
| Jul 28, 2020 | Discovery Bay, at Beacon Bay | Caution | Lake-wide advisory |
| Jun 22, 2020 | Discovery Bay, at Windward Bay | Caution | visual monitoring based advisory |
| Jun 12, 2020 | Discovery Bay, Starboard Bay | Caution | visual monitoring based advisory |
| Jun 10, 2020 | Discovery Bay, Cypress Channel | Danger | Advisory based on visual and toxins |
| Jun 10, 2020 | Discovery Bay, Reef Cove | Danger | Advisory based on visual and toxins |
| Jun 10, 2020 | Discovery Bay, at yacht harbor | Danger | Advisory based on visual and toxins |
| Jun 10, 2020 | Discovery Bay, Indian Bay | Caution | Lake-wide advisory |
| Jun 5, 2020 | Discovery Bay, at Kellogg Creek | NA - refer to Report Details | |
| Jul 8, 2019 | Discovery Bay - E Dock at Yacht Harbor | Caution | |
| May 17, 2019 | Discovery Bay - Boardwalk Grill in Yacht Harbor | Caution | |
| Dec 4, 2018 | Discovery Bay, near Capstan Place | None | |
| Dec 4, 2018 | Discovery Bay - Multiple Locations Within Entire Bay | None | |
| Dec 4, 2018 | Driftwood Bay inside Discovery Bay | None | |
| Nov 3, 2017 | Discovery Bay near Newport Drive | None | |
| Sep 9, 2016 | Discovery Bay | Warning |
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.