Topaz Lake: toxic algae advisories
Topaz Lake, Mono County. See all Mono County waters.
What the state's records say
The state's latest record, from Sep 30, 2026, recommends no advisory.
Last advisory on file: Aug 22, 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 Topaz Lake
The state's latest record, from Sep 30, 2026, recommends no advisory. For Topaz 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 |
|---|---|
| Pullout South of Ag Station | The state's latest record, from Sep 30, 2026, recommends no advisory. |
| South End | The state's latest record, from Oct 19, 2022, recommends no advisory. |
| south of Agriculture check pullout | The state's latest record, from Sep 8, 2022, recommends no advisory. |
| pullout south of agricultural station | The state's latest record, from Jun 28, 2021, recommends no advisory. |
| Topaz Lake, southern end (CA) | The state's latest record, from Sep 2, 2020, recommends no advisory. |
Advisory history
Every advisory record the state has published for Topaz 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 |
|---|---|---|---|
| Sep 30, 2026 | Pullout South of Ag Station | None | Advisory based on visual and toxins; Confirmed no bloom; Testing results below posting triggers |
| Aug 28, 2026 | Pullout South of Ag Station | None | Advisory based on visual and toxins; Confirmed no bloom; Testing results below posting triggers |
| Jun 25, 2026 | Pullout South of Ag Station | None | Advisory based on visual and toxins; Confirmed no bloom; Testing results below posting triggers |
| Oct 14, 2025 | Pullout South of Ag Station | None | Advisory based on visual and toxins; Confirmed no bloom; Testing results below posting triggers |
| Aug 22, 2025 | Pullout South of Ag Station | Visual observation | Advisory based on visual and toxins; Testing results below posting triggers |
| Jun 26, 2025 | Pullout South of Ag Station | None | Advisory based on visual and toxins |
| Oct 9, 2024 | Pullout South of Ag Station | None | Advisory based on visual and toxins |
| Aug 27, 2024 | Pullout South of Ag Station | None | Advisory based on visual and toxins |
| Jun 20, 2024 | Pullout South of Ag Station | None | Advisory based on visual and toxins |
| Sep 29, 2023 | Pullout South of Ag Station | Caution | Advisory based on visual and toxins |
| Sep 21, 2023 | Pullout South of Ag Station | Visual observation | Visual monitoring only-present bloom |
| Aug 29, 2023 | Pullout South of Ag Station | None | Updates from routine monitoring program-organization |
| Jul 5, 2023 | Pullout South of Ag Station | None | Updates from routine monitoring program-organization |
| Oct 19, 2022 | South End | None | Testing results below posting triggers |
| Sep 8, 2022 | south of Agriculture check pullout | None | Testing results below posting triggers |
| Jun 23, 2022 | south of Agriculture check pullout | None | Testing results below posting triggers |
| Jun 3, 2022 | south of Agriculture check pullout | None | Testing results below posting triggers |
| Jun 28, 2021 | pullout south of agricultural station | None | Testing results below posting triggers |
| Sep 2, 2020 | Topaz Lake, southern end (CA) | 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.