San Bernardino County: lake and river algae advisories
36 waters in San Bernardino County appear in the state's harmful algal bloom records. Waters whose latest record is an advisory come first.
| Water | Latest record |
|---|---|
| Ben Williams River Wildlife Refuge | Warning advisory, last posted Oct 21, 2022. No all-clear recorded. |
| Big Bear Lake | Danger advisory, last posted Aug 28, 2026. No all-clear recorded. |
| Big bear lake ca | Caution advisory, last posted Aug 18, 2026. No all-clear recorded. |
| Colorado River | Caution advisory, last posted Dec 7, 2022. No all-clear recorded. |
| Crab Creek | Algal mat alert sign, last posted Jun 19, 2026. No all-clear recorded. |
| Cucamonga-Guasti Regional Park | Caution advisory, last posted Aug 29, 2024. No all-clear recorded. |
| Glen Helen Regional Park | Caution advisory, last posted Sep 1, 2020. No all-clear recorded. |
| Green Valley Lake | Caution advisory, last posted Jul 28, 2023. No all-clear recorded. |
| Lake Gregory | Caution advisory, last posted Aug 29, 2024. No all-clear recorded. |
| Lake Havasu | Danger advisory, last posted Jun 29, 2026. No all-clear recorded. |
| Mill Creek | General awareness, last posted Jul 1, 2026. No all-clear recorded. |
| Prado Regional Park | Danger advisory, last posted Sep 4, 2026. No all-clear recorded. |
| Santa Ana River | Algal mat general awareness sign, last posted Sep 25, 2026. No all-clear recorded. |
| Silverwood Lake | Caution advisory, last posted Oct 19, 2026. No all-clear recorded. |
| Yucaipa Regional Park | Caution advisory, last posted May 14, 2026. No all-clear recorded. |
| Yuciapa Regional Park | Caution advisory, last posted Oct 9, 2020. No all-clear recorded. |
| Bill Williams River | The state's latest record, from Dec 7, 2022, recommends no advisory. |
| City Creek | The state's latest record, from Jun 19, 2026, recommends no advisory. |
| Deep Creek | The state's latest record, from Jun 27, 2024, recommends no advisory. |
| Devil's Canyon | The state's latest record, from Jun 26, 2026, recommends no advisory. |
| Grass Valley Lake | The state's latest record, from Sep 2, 2022, recommends no advisory. |
| Holcomb Creek | The state's latest record, from Jun 19, 2026, recommends no advisory. |
| Horseshoe Lake | The state's latest record, from Sep 3, 2026, recommends no advisory. |
| Lake Arrowhead | The state's latest record, from Sep 2, 2022, recommends no advisory. |
| Lytle Creek | The state's latest record, from Jul 1, 2026, recommends no advisory. |
| Metcalf Creek | The state's latest record, from Jul 7, 2023, recommends no advisory. |
| Mid Grout Creek | The state's latest record, from Jun 27, 2024, recommends no advisory. |
| Mojave Narrows Regional Park | The state's latest record, from Jun 30, 2022, recommends no advisory. |
| Mojave River | The state's latest record, from Jun 26, 2026, recommends no advisory. |
| Owl Hole Spring | Reports on file, with no advisory level the state has classified. |
| Pelican Lake | The state's latest record, from Sep 3, 2026, recommends no advisory. |
| Rathbun Creek | The state's latest record, from Jul 7, 2023, recommends no advisory. |
| San Timoteo Wash | The state's latest record, from May 10, 2024, recommends no advisory. |
| Santa Ana River Random | The state's latest record, from May 20, 2022, recommends no advisory. |
| Spring Valley Lake | The state's latest record, from Aug 25, 2026, recommends no advisory. |
| Unnamed channel | Reports on file, with no advisory level the state has classified. |