College Lake: toxic algae advisories
College Lake, Santa Cruz County. See all Santa Cruz County waters.
What the state's records say
The state recorded an end date of Jun 12, 2025.
Last advisory on file: Aug 7, 2025.
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 College Lake
The state recorded an end date of Jun 12, 2025. For College Lake, 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 |
|---|---|
| outlet | The state recorded an end date of Jun 12, 2025. |
Advisory history
Every advisory record the state has published for College Lake, 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 |
|---|---|---|---|
| Aug 7, 2025 | outlet | Caution | End date recorded: Jun 12, 2025. Updates from routine monitoring program-organization |
| Jul 31, 2025 | outlet | Caution | End date recorded: Jun 12, 2025. Updates from routine monitoring program-organization |
| Jul 9, 2025 | outlet | None | End date recorded: Jun 12, 2025. Updates from routine monitoring program-organization |
| Jun 26, 2025 | outlet | None | End date recorded: Jun 12, 2025. Updates from routine monitoring program-organization |
| Jun 12, 2025 | outlet | None | End date recorded: Jun 12, 2025. Updates from routine monitoring program-organization |
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.