San Gregorio Creek: toxic algae advisories
San Gregorio Creek, San Mateo County. See all San Mateo County waters.
What the state's records say
The state recorded an end date of Dec 31, 2022.
Last advisory on file: May 8, 2023.
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 San Gregorio Creek
The state recorded an end date of Dec 31, 2022. For San Gregorio 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 |
|---|---|
| San Gregorio State Beach | The state recorded an end date of Dec 31, 2022. |
Advisory history
Every advisory record the state has published for San Gregorio 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 8, 2023 | San Gregorio State Beach | Algal mat alert sign | End date recorded: Dec 31, 2022. Updates from routine monitoring program-organization |
| May 8, 2023 | San Gregorio State Beach | Algal mat alert sign | End date recorded: Dec 31, 2022. Updates from routine monitoring program-organization |
| Aug 30, 2022 | San Gregorio State Beach | Algal mat alert sign | End date recorded: Dec 31, 2022. Updates from routine monitoring program-organization |
| Aug 30, 2022 | San Gregorio State Beach | Algal mat alert sign | End date recorded: Dec 31, 2022. Updates from routine monitoring program-organization |
| Aug 30, 2022 | San Gregorio State Beach | Algal mat alert sign | Updates from routine monitoring program-organization |
| Jun 29, 2022 | San Gregorio State Beach | Algal mat alert sign | Updates from routine monitoring program-organization |
| May 20, 2022 | San Gregorio State Beach | None | Testing results below posting triggers |
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.