Sweetwater River: toxic algae advisories
Sweetwater River, San Diego County. See all San Diego County waters.
What the state's records say
The state's latest record, from Aug 25, 2025, recommends no advisory.
Last advisory on file: Aug 29, 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 Sweetwater River
The state's latest record, from Aug 25, 2025, recommends no advisory. For Sweetwater River, 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 |
|---|---|
| Green Valley Falls | The state's latest record, from Aug 25, 2025, recommends no advisory. |
| at Morrison Pond just upstream of Sweetwater Road | The state's latest record, from Sep 9, 2024, recommends no advisory. |
Advisory history
Every advisory record the state has published for Sweetwater 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 |
|---|---|---|---|
| Aug 25, 2025 | Green Valley Falls | None | No cyano bloom w/testing |
| Jul 1, 2025 | Green Valley Falls | None | No cyano bloom w/testing |
| May 14, 2025 | Green Valley Falls | None | No cyano bloom w/testing |
| Sep 9, 2024 | at Morrison Pond just upstream of Sweetwater Road | None | End date recorded: Jan 4, 2023. Testing results below posting triggers |
| Aug 29, 2022 | at Morrison Pond just upstream of Sweetwater Road | Caution | End date recorded: Jan 4, 2023. Advisory based on visual and toxins |
| Aug 29, 2022 | at Morrison Pond just upstream of Sweetwater Road | Caution | Advisory based on visual and toxins |
| Aug 29, 2022 | at Morrison Pond just upstream of Sweetwater Road | Caution | Advisory based on visual and toxins |
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.