Sonoma County: lake and river algae advisories
18 waters in Sonoma County appear in the state's harmful algal bloom records. Waters whose latest record is an advisory come first.
| Water | Latest record |
|---|---|
| Gualala River | Algal mat general awareness sign, last posted Jul 27, 2022. No all-clear recorded. |
| Lake Ralphine | Warning advisory, last posted Jul 20, 2026. No all-clear recorded. |
| Pacific Ocean | Caution advisory, last posted Oct 30, 2024. No all-clear recorded. |
| Ringstrom Unit Marsh | Caution advisory, last posted Jun 25, 2026. No all-clear recorded. |
| Russian River | Algal mat alert sign, last posted Oct 19, 2026. No all-clear recorded. |
| Salmon Creek | Algal mat alert sign, last posted Aug 27, 2026. No all-clear recorded. |
| Salmon Creek Lagoon | Caution advisory, last posted Jun 30, 2020. No all-clear recorded. |
| San Pablo Bay | Caution advisory, last posted Sep 7, 2022. No all-clear recorded. |
| Sonoma Creek | Algal mat alert sign, last posted Aug 18, 2026. No all-clear recorded. |
| Spring Lake | Visual observation, last posted May 29, 2026. No all-clear recorded. |
| Stockhoff Creek | Algal mat general awareness sign, last posted Jul 18, 2024. No all-clear recorded. |
| Austin Creek | The state's latest record, from Jun 6, 2022, recommends no advisory. |
| Lake Nagasawa | Reports on file, with no advisory level the state has classified. |
| Lake Sonoma | The state's latest record, from Aug 27, 2026, recommends no advisory. |
| Matanzas Creek | The state's latest record, from Jun 4, 2024, recommends no advisory. |
| Paulin Creek | The state's latest record, from Aug 18, 2022, recommends no advisory. |
| Petaluma River | The state's latest record, from May 19, 2026, recommends no advisory. |
| Yorty Creek | The state's latest record, from Apr 17, 2026, recommends no advisory. |