Unnamed Tributary to Onion Creek: toxic algae advisories
Unnamed Tributary to Onion Creek, Placer County. See all Placer County waters.
What the state's records say
The state's latest record, from May 20, 2026, recommends no advisory.
That reflects what the state knew on that date. It is not a finding that the water is safe now: blooms can return within days, and many are never reported.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Unnamed Tributary to Onion Creek
The state's latest record, from May 20, 2026, recommends no advisory. For Unnamed Tributary to Onion Creek, that is not the same as an all-clear for today. Look at the water before your dog goes in: keep it out of green, blue-green or scummy water and away from mats on the shore.
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 |
|---|---|
| at Soda Springs Rd (514TRBONN) | The state's latest record, from May 20, 2026, recommends no advisory. |
Advisory history
Every advisory record the state has published for Unnamed Tributary to Onion Creek, 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 |
|---|---|---|---|
| May 20, 2026 | at Soda Springs Rd (514TRBONN) | 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.