Lake County: lake and river algae advisories
23 waters in Lake County appear in the state's harmful algal bloom records. Waters whose latest record is an advisory come first.
| Water | Latest record |
|---|---|
| Cache Creek | Caution advisory, last posted Jul 11, 2024. No all-clear recorded. |
| Clear Lake | Danger advisory, last posted Sep 4, 2026. No all-clear recorded. |
| Copsey Creek | Danger advisory, last posted Jul 26, 2024. No all-clear recorded. |
| Forbes Creek | Warning advisory, last posted Jul 22, 2024. No all-clear recorded. |
| Kelsey Creek | Caution advisory, last posted Jul 14, 2021. No all-clear recorded. |
| Lake Pillsbury | Danger advisory, last posted Oct 19, 2026. No all-clear recorded. |
| Manning Creek | Caution advisory, last posted Jul 1, 2022. No all-clear recorded. |
| Putah Creek | Caution advisory, last posted Aug 21, 2026. No all-clear recorded. |
| Seiger Canyon Creek | Caution advisory, last posted Jul 1, 2022. No all-clear recorded. |
| St. Helena Creek | Algal mat alert sign, last posted Jul 12, 2022. No all-clear recorded. |
| Stanton Creek | Algal mat alert sign, last posted Jun 16, 2022. No all-clear recorded. |
| Upper Blue Lake | Caution advisory, last posted Dec 18, 2019. No all-clear recorded. |
| Bear Creek | The state's latest record, from Jun 11, 2024, recommends no advisory. |
| Blue Lakes | The state recorded an end date of Jul 27, 2022. |
| Blue Slides Creek | The state's latest record, from Jun 26, 2025, recommends no advisory. |
| Borax Lake | The state's latest record, from May 9, 2018, recommends no advisory. |
| Hidden Valley Lake | Reports on file, with no advisory level the state has classified. |
| Highland Creek | The state's latest record, from Jun 26, 2023, recommends no advisory. |
| Lower Blue Lake | The state's latest record, from Oct 17, 2024, recommends no advisory. |
| Middle Creek | The state's latest record, from Apr 17, 2026, recommends no advisory. |
| Unnamed tributary to Eel River | The state's latest record, from Apr 17, 2026, recommends no advisory. |
| Upper and Lower Blue Lakes | The state's latest record, from Sep 11, 2017, recommends no advisory. |
| Welch Creek | The state's latest record, from Apr 17, 2026, recommends no advisory. |