Lake Almanor: toxic algae advisories
Lake Almanor, Plumas County. See all Plumas County waters.
What the state's records say
Caution advisory, last posted Sep 10, 2026. No all-clear recorded.
7 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: Algae that can make toxins may be present. Keep people, children and pets away from algae and scum, and do not let pets drink the water.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Lake Almanor
The state has an advisory on file for Lake Almanor (Caution advisory), last posted Sep 10, 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.
Satellite estimate (not an advisory)
No satellite reading on file for Lake Almanor in recent weeks. Clouds, ice, or a lake shape the satellite's estimate near its center misses can cause this. It is a gap in the data, not a reading.
This is a satellite estimate from the U.S. EPA's Cyanobacteria Assessment Network, not an advisory. It estimates how much cyanobacteria is in the water near the lake's center, not whether toxins are present: a high number does not mean toxins, and a low one does not mean there are none. It covers lakes of about 1 square kilometer and larger, so small ponds, dog parks and most rivers are not covered, and clouds can hide a lake for weeks. It never changes the advisory status above.
Satellite estimates: U.S. EPA Cyanobacteria Assessment Network (CyAN), from Copernicus Sentinel-3 data. Provisional, research-level estimates; EPA does not endorse this site. Checked Oct 22, 2026.
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 |
|---|---|
| Cove near Lakeview Terrace | Caution advisory, last posted Sep 10, 2026. No all-clear recorded. |
| East of Lake Almanor West | Caution advisory, last posted Oct 18, 2022. No all-clear recorded. |
| Lake Almanor Country Club Rec Area 1 | The state's latest record, from Oct 18, 2022, recommends no advisory. |
| Almanor Boat Launch North of Prattville | Caution advisory, last posted Oct 18, 2022. No all-clear recorded. |
| Mid North Basin | Caution advisory, last posted Oct 18, 2022. No all-clear recorded. |
| Chester | The state's latest record, from Aug 29, 2022, recommends no advisory. |
| 1 | Caution advisory, last posted Nov 15, 2021. No all-clear recorded. |
| Rocky Point Campground | The state's latest record, from Sep 13, 2021, recommends no advisory. |
| North Shore Campground | The state's latest record, from Sep 13, 2021, recommends no advisory. |
| Marvin Alexander Beach | The state's latest record, from Sep 13, 2021, recommends no advisory. |
| East Shore | The state's latest record, from Sep 13, 2021, recommends no advisory. |
| Catfish Beach | The state's latest record, from Sep 13, 2021, recommends no advisory. |
| Lake Almanor West | Caution advisory, last posted Sep 1, 2021. No all-clear recorded. |
| Lake Almanor | Caution advisory, last posted Oct 27, 2020. No all-clear recorded. |
| Last Chance arm of Lake Almanor | The state's latest record, from Oct 22, 2019, recommends no advisory. |
| Lake Almanor-north arm | The state's latest record, from Dec 4, 2018, recommends no advisory. |
Advisory history
Every advisory record the state has published for Lake Almanor, 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 |
|---|---|---|---|
| Sep 10, 2026 | Cove near Lakeview Terrace | Caution | Under investigation |
| Oct 18, 2022 | East of Lake Almanor West | Caution | Floating/planktonic bloom observed |
| Oct 18, 2022 | Lake Almanor Country Club Rec Area 1 | None | Rec general awareness |
| Oct 18, 2022 | Almanor Boat Launch North of Prattville | Caution | Advisory based on visual and toxins; Floating/planktonic bloom observed |
| Oct 18, 2022 | Mid North Basin | Caution | Advisory based on visual and toxins |
| Oct 18, 2022 | Mid North Basin | Caution | Advisory based on visual and toxins |
| Sep 30, 2022 | East of Lake Almanor West | Caution | Floating/planktonic bloom observed |
| Sep 30, 2022 | East of Lake Almanor West | Caution | Lake-wide advisory; No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Sep 29, 2022 | Lake Almanor Country Club Rec Area 1 | None | Advisory based on visual and toxins; Floating/planktonic bloom observed |
| Sep 29, 2022 | Almanor Boat Launch North of Prattville | Caution | Advisory based on visual and toxins; Floating/planktonic bloom observed |
| Aug 29, 2022 | East of Lake Almanor West | None | No cyano bloom w/testing; Updates from routine monitoring program-organization |
| Aug 29, 2022 | Almanor Boat Launch North of Prattville | None | No cyano bloom w/testing |
| Aug 29, 2022 | Chester | None | No cyano bloom w/testing |
| Aug 29, 2022 | Lake Almanor Country Club Rec Area 1 | None | No cyano bloom w/testing |
| Aug 29, 2022 | Almanor Boat Launch North of Prattville | None | No cyano bloom w/testing |
| Aug 29, 2022 | Chester | None | No cyano bloom w/testing |
| Jun 20, 2022 | Lake Almanor Country Club Rec Area 1 | None | No cyano bloom w/testing |
| Jun 20, 2022 | Almanor Boat Launch North of Prattville | None | No cyano bloom w/testing |
| Jun 20, 2022 | Chester | None | No cyano bloom w/testing |
| May 25, 2022 | Lake Almanor Country Club Rec Area 1 | None | No cyano bloom w/testing |
| May 25, 2022 | Almanor Boat Launch North of Prattville | None | No cyano bloom w/testing |
| May 25, 2022 | Chester | None | No cyano bloom w/testing |
| Nov 15, 2021 | 1 | Caution | visual monitoring based advisory |
| Sep 13, 2021 | Rocky Point Campground | None | Testing results below posting triggers |
| Sep 13, 2021 | North Shore Campground | None | Testing results below posting triggers |
| Sep 13, 2021 | Marvin Alexander Beach | None | Testing results below posting triggers |
| Sep 13, 2021 | East Shore | None | Testing results below posting triggers |
| Sep 13, 2021 | Catfish Beach | None | Testing results below posting triggers |
| Sep 1, 2021 | Lake Almanor West | Caution | visual monitoring based advisory |
| Oct 27, 2020 | Lake Almanor | Caution | Advisory based on visual and toxins |
| Oct 22, 2019 | Last Chance arm of Lake Almanor | None | |
| Dec 4, 2018 | Lake Almanor-north arm | None |
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.