Marin County: lake and river algae advisories
19 waters in Marin County appear in the state's harmful algal bloom records. Waters whose latest record is an advisory come first.
| Water | Latest record |
|---|---|
| Bel Marin Keys | Caution advisory, last posted Dec 17, 2020. No all-clear recorded. |
| Marin Civic Center Lagoon | Visual observation, last posted Jun 5, 2025. No all-clear recorded. |
| Nicasio Reservoir | Caution advisory, last posted May 19, 2021. No all-clear recorded. |
| Novato Creek | Caution advisory, last posted Apr 26, 2024. No all-clear recorded. |
| Richardson Bay | Caution advisory, last posted Jul 31, 2023. No all-clear recorded. |
| Rush Creek Marsh Wildlife Area | Caution advisory, last posted May 12, 2026. No all-clear recorded. |
| San Francisco Bay, Central | Visual observation, last posted Aug 1, 2023. No all-clear recorded. |
| Scottsdale Pond | Warning advisory, last posted Jul 8, 2025. No all-clear recorded. |
| Stafford Lake | Warning advisory, last posted Oct 9, 2026. No all-clear recorded. |
| Tomales Bay | Caution advisory, last posted Oct 31, 2024. No all-clear recorded. |
| Unnamed Creek | Algal mat general awareness sign, last posted Sep 8, 2021. No all-clear recorded. |
| Arroyo Hondo Creek | The state's latest record, from Jun 11, 2026, recommends no advisory. |
| Arroyo San Jose | The state's latest record, from May 1, 2025, recommends no advisory. |
| Lagunitas Creek | The state's latest record, from Aug 30, 2022, recommends no advisory. |
| Muddy Hollow Creek | The state's latest record, from Jun 11, 2026, recommends no advisory. |
| Pine Gulch Creek | The state's latest record, from Jun 11, 2026, recommends no advisory. |
| San Geronimo Creek | The state's latest record, from Jun 27, 2023, recommends no advisory. |
| Unnamed Lagoon | The state recorded an end date of Dec 31, 2022. |
| Unnamed Tributary to Big Carson Creek | The state's latest record, from Jun 11, 2026, recommends no advisory. |