Redwood Creek: toxic algae advisories
Redwood Creek, Napa County. See all Napa County waters.
What the state's records say
The state's latest record, from Jul 1, 2026, recommends no advisory.
Last advisory on file: May 16, 2022.
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 Redwood Creek
The state's latest record, from Jul 1, 2026, recommends no advisory. For Redwood 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 |
|---|---|
| Redwood Creek at Alston Park (206RED140) | The state's latest record, from Jul 1, 2026, recommends no advisory. |
| southwestern section of Alston Park | The state's latest record, from May 23, 2022, recommends no advisory. |
Advisory history
Every advisory record the state has published for Redwood 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 |
|---|---|---|---|
| Jul 1, 2026 | Redwood Creek at Alston Park (206RED140) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 27, 2024 | Redwood Creek at Alston Park (206RED140) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 27, 2024 | Redwood Creek at Alston Park (206RED140) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| May 23, 2022 | southwestern section of Alston Park | None | End date recorded: Dec 31, 2022. No cyano bloom w/testing |
| May 23, 2022 | southwestern section of Alston Park | None | End date recorded: May 26, 2022. No cyano bloom w/testing |
| May 16, 2022 | southwestern section of Alston Park | Caution | Suspected illness reported |
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.