Copco Reservoir: toxic algae advisories
Copco Reservoir, Siskiyou County. See all Siskiyou County waters.
What the state's records say
Danger advisory, last posted Nov 7, 2023. No all-clear recorded.
6 reported spots here have an advisory with no all-clear recorded.
Reporting is voluntary, so the state may not have recorded an end even if conditions changed. Check posted signs and the official map.
What this level asks: Toxins may be at levels that can seriously harm people and animals. Stay out of the water and keep children and pets away from the water and the shore.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Copco Reservoir
The state has an advisory on file for Copco Reservoir (Danger advisory), last posted Nov 7, 2023, and no all-clear recorded. Keep your dog out of the water and away from scum on the shore until the state records an end.
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 |
|---|---|
| at Mallard Cove (Public Health) | The state's latest record, from Dec 18, 2023, recommends no advisory. |
| at Copco Cove (Public Health) | The state's latest record, from Dec 18, 2023, recommends no advisory. |
| at Bouy Line (RM 198.74) | Caution advisory, last posted Nov 7, 2023. No all-clear recorded. |
| at Copco Cove (Public Health) | The state's latest record, from Dec 16, 2022, recommends no advisory. |
| at Mallard Cove (Public Health) | The state's latest record, from Dec 16, 2022, recommends no advisory. |
| at Buoy Line (RM 198.74) | The state's latest record, from Dec 16, 2022, recommends no advisory. |
| at Mallard Cove?(Public Health) | Danger advisory, last posted Jul 21, 2021. No all-clear recorded. |
| at Copco Cove?(Public Health) | Danger advisory, last posted Jul 21, 2021. No all-clear recorded. |
| at Bouy Line (RM 198.74) | Danger advisory, last posted Jul 21, 2021. No all-clear recorded. |
| Copco Reservoir, at Mallard Cove (CRMC) | Danger advisory, last posted Oct 19, 2020. No all-clear recorded. |
| Copco Reservoir, at Copco Cove (CRCC) | Danger advisory, last posted Oct 19, 2020. No all-clear recorded. |
| Copco Reservoir at Mallard Cove | Reports on file, with no advisory level the state has classified. |
| Copco Reservoir at Copco Cove | Reports on file, with no advisory level the state has classified. |
Advisory history
Every advisory record the state has published for Copco Reservoir, 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 |
|---|---|---|---|
| Dec 18, 2023 | at Mallard Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Dec 18, 2023 | at Copco Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Dec 5, 2023 | at Copco Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Dec 5, 2023 | at Mallard Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Nov 20, 2023 | at Copco Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Nov 20, 2023 | at Mallard Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Nov 12, 2023 | at Mallard Cove (Public Health) | Caution | Advisory based on visual and toxins; Floating/planktonic bloom observed; Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 12, 2023 | at Copco Cove (Public Health) | Caution | Advisory based on visual and toxins; Floating/planktonic bloom observed; Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 7, 2023 | at Copco Cove (Public Health) | Caution | Advisory based on visual and toxins; Floating/planktonic bloom observed; Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 7, 2023 | at Mallard Cove (Public Health) | Caution | Advisory based on visual and toxins; Floating/planktonic bloom observed; Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 7, 2023 | at Bouy Line (RM 198.74) | Caution | Advisory based on visual and toxins; Floating/planktonic bloom observed; Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 9, 2023 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 9, 2023 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 21, 2023 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 21, 2023 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 21, 2023 | at Bouy Line (RM 198.74) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 1, 2023 | at Mallard Cove (Public Health) | Warning | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 1, 2023 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 1, 2023 | at Copco Cove (Public Health) | Warning | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 1, 2023 | at Mallard Cove (Public Health) | Warning | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 18, 2023 | at Bouy Line (RM 198.74) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 18, 2023 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 18, 2023 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 2, 2023 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 2, 2023 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 27, 2023 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 27, 2023 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 27, 2023 | at Copco Cove (Public Health) | Danger | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jul 27, 2023 | at Bouy Line (RM 198.74) | Danger | Alert-high concentration toxins; Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 30, 2023 | at Mallard Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 30, 2023 | at Copco Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 16, 2023 | at Mallard Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 16, 2023 | at Copco Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 16, 2023 | at Bouy Line (RM 198.74) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 5, 2023 | at Mallard Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 5, 2023 | at Copco Cove (Public Health) | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Dec 16, 2022 | at Copco Cove (Public Health) | None | End date recorded: Dec 16, 2022. De-posting advisory. |
| Dec 16, 2022 | at Mallard Cove (Public Health) | None | End date recorded: Dec 16, 2022. De-posting advisory. |
| Dec 16, 2022 | at Buoy Line (RM 198.74) | None | End date recorded: Dec 16, 2022. De-posting advisory. |
| Dec 16, 2022 | at Buoy Line (RM 198.74) | None | De-posting advisory. |
| Dec 16, 2022 | at Mallard Cove (Public Health) | None | De-posting advisory. |
| Dec 16, 2022 | at Copco Cove (Public Health) | None | De-posting advisory. |
| Nov 28, 2022 | at Mallard Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Nov 28, 2022 | at Copco Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Nov 14, 2022 | at Copco Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Nov 14, 2022 | at Mallard Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 20, 2022 | at Mallard Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 20, 2022 | at Copco Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 20, 2022 | at Buoy Line (RM 198.74) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 6, 2022 | at Buoy Line (RM 198.74) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 6, 2022 | at Mallard Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 6, 2022 | at Copco Cove (Public Health) | Caution | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 3, 2022 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 3, 2022 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Oct 3, 2022 | at Buoy Line (RM 198.74) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Sep 8, 2022 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Sep 7, 2022 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Sep 7, 2022 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Aug 24, 2022 | at Mallard Cove (Public Health) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Aug 24, 2022 | at Copco Cove (Public Health) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Aug 24, 2022 | at Buoy Line (RM 198.74) | Danger | Alert-high concentration toxins; Updates from routine monitoring program-organization |
| Aug 8, 2022 | at Mallard Cove (Public Health) | Danger | Updates from routine monitoring program-organization |
| Aug 8, 2022 | at Buoy Line (RM 198.74) | Danger | Updates from routine monitoring program-organization |
| Aug 8, 2022 | at Copco Cove (Public Health) | Danger | Updates from routine monitoring program-organization |
| Jul 25, 2022 | at Copco Cove (Public Health) | Danger | Updates from routine monitoring program-organization |
| Jul 25, 2022 | at Buoy Line (RM 198.74) | Danger | Updates from routine monitoring program-organization |
| Jul 22, 2022 | at Mallard Cove (Public Health) | Danger | Updates from routine monitoring program-organization |
| Jul 22, 2022 | at Copco Cove (Public Health) | Danger | Updates from routine monitoring program-organization |
| Jul 1, 2022 | at Mallard Cove (Public Health) | Caution | Updates from routine monitoring program-organization |
| Jul 1, 2022 | at Copco Cove (Public Health) | Caution | Updates from routine monitoring program-organization |
| Jun 30, 2022 | at Copco Cove (Public Health) | Caution | Updates from routine monitoring program-organization |
| Jun 17, 2022 | at Buoy Line (RM 198.74) | Caution | Updates from routine monitoring program-organization |
| Jun 17, 2022 | at Mallard Cove (Public Health) | Caution | Updates from routine monitoring program-organization |
| Jun 17, 2022 | at Buoy Line (RM 198.74) | None | Updates from routine monitoring program-organization |
| Jun 17, 2022 | at Copco Cove (Public Health) | Caution | Updates from routine monitoring program-organization |
| Jun 3, 2022 | at Mallard Cove (Public Health) | None | Updates from routine monitoring program-organization |
| Jun 3, 2022 | at Copco Cove (Public Health) | None | Updates from routine monitoring program-organization |
| Jun 3, 2022 | at Copco Cove (Public Health) | None | Updates from routine monitoring program-organization |
| May 20, 2022 | at Buoy Line (RM 198.74) | None | Updates from routine monitoring program-organization |
| May 20, 2022 | at Buoy Line (RM 198.74) | None | Updates from routine monitoring program-organization |
| May 19, 2022 | at Copco Cove (Public Health) | None | Updates from routine monitoring program-organization |
| Jan 11, 2022 | at Mallard Cove (Public Health) | None | Updates from routine monitoring program-organization |
| Jul 21, 2021 | at Mallard Cove?(Public Health) | Danger | Advisory based on visual and toxins |
| Jul 21, 2021 | at Copco Cove?(Public Health) | Danger | Advisory based on visual and toxins |
| Jul 21, 2021 | at Bouy Line (RM 198.74) | Danger | Advisory based on visual and toxins |
| Oct 19, 2020 | Copco Reservoir, at Mallard Cove (CRMC) | Danger | Advisory based on visual and toxins |
| Oct 19, 2020 | Copco Reservoir, at Copco Cove (CRCC) | Danger | Advisory based on visual and toxins |
| Sep 29, 2018 | Copco Reservoir at Mallard Cove | NA - refer to Report Details | |
| Sep 29, 2018 | Copco Reservoir at Copco Cove | NA - refer to Report Details |
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.