American River: toxic algae advisories
American River, Sacramento County. See all Sacramento County waters.
What the state's records say
Caution advisory, last posted Sep 29, 2025. No all-clear recorded.
3 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 American River
The state has an advisory on file for American River (Caution advisory), last posted Sep 29, 2025, 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.
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 |
|---|---|
| 700 feet downstream of Watt Ave Bridge near small island | General awareness, last posted Sep 29, 2025. No all-clear recorded. |
| Paradise Beach | Caution advisory, last posted Sep 1, 2021. No all-clear recorded. |
| American River, Paradise Beach | Algal mat general awareness sign, last posted Apr 30, 2020. No all-clear recorded. |
| Discovery Park south entrance | The state's latest record, from Apr 23, 2018, recommends no advisory. |
Advisory history
Every advisory record the state has published for American River, 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 29, 2025 | 700 feet downstream of Watt Ave Bridge near small island | General awareness | Testing results below posting triggers |
| Sep 11, 2025 | 700 feet downstream of Watt Ave Bridge near small island | NA - refer to Report Details | Under investigation |
| Sep 1, 2021 | Paradise Beach | Caution | visual monitoring based advisory |
| Apr 30, 2020 | American River, Paradise Beach | Algal mat general awareness sign | |
| Apr 23, 2018 | Discovery Park south entrance | 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.