Silverwood Lake: toxic algae advisories
Silverwood Lake, San Bernardino County. See all San Bernardino County waters.
What the state's records say
Caution advisory, last posted Oct 19, 2026. No all-clear recorded.
8 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: Algae that can make toxins may be present. Keep people, children and pets away from algae and scum, and do not let pets drink the water.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Silverwood Lake
The state has an advisory on file for Silverwood Lake (Caution advisory), last posted Oct 19, 2026, 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.
Satellite estimate (not an advisory)
Week ending Oct 17, 2026: about 20,000 cells/mL of cyanobacteria near the center of Silverwood Lake.
A satellite estimate from EPA CyAN for a 3.7 km² lake. It does not measure toxins and does not change the advisory status.
| Week ending | Estimate |
|---|---|
| Oct 17, 2026 | about 20,000 cells/mL |
| Jul 18, 2026 | about 540,000 cells/mL |
| Jul 4, 2026 | about 310,000 cells/mL |
| Jun 27, 2026 | about 110,000 cells/mL |
| May 23, 2026 | about 350,000 cells/mL |
| Aug 23, 2025 | about 190,000 cells/mL |
| Aug 16, 2025 | about 170,000 cells/mL |
| Aug 9, 2025 | about 46,000 cells/mL |
This is a satellite estimate from the U.S. EPA's Cyanobacteria Assessment Network, not an advisory. It estimates how much cyanobacteria is in the water near the lake's center, not whether toxins are present: a high number does not mean toxins, and a low one does not mean there are none. It covers lakes of about 1 square kilometer and larger, so small ponds, dog parks and most rivers are not covered, and clouds can hide a lake for weeks. It never changes the advisory status above.
Satellite estimates: U.S. EPA Cyanobacteria Assessment Network (CyAN), from Copernicus Sentinel-3 data. Provisional, research-level estimates; EPA does not endorse this site. Checked Oct 22, 2026.
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 |
|---|---|
| Silverwood Lake outlet | Caution advisory, last posted Oct 19, 2026. No all-clear recorded. |
| Silverwood Lake Sawpit Swim Beach | Caution advisory, last posted Oct 19, 2026. No all-clear recorded. |
| Silverwood Lake Cleghorn Swim Beach | Caution advisory, last posted Oct 19, 2026. No all-clear recorded. |
| Silverwood Lake outlet | Caution advisory, last posted Sep 8, 2026. No all-clear recorded. |
| Miller Canyon | The state's latest record, from May 8, 2025, recommends no advisory. |
| Marina | The state's latest record, from May 8, 2025, recommends no advisory. |
| Willows cove | The state's latest record, from Jul 5, 2024, recommends no advisory. |
| Silverwood Lake Sawpit Swim Beach | The state's latest record, from Dec 15, 2022, recommends no advisory. |
| Silverwood Lake Cleghorn Swim Beach | The state's latest record, from Dec 15, 2022, recommends no advisory. |
| outlet | The state's latest record, from Jul 12, 2021, recommends no advisory. |
| Cleghorn Swim Beach | Caution advisory, last posted Jul 12, 2021. No all-clear recorded. |
| Sawpit Swim Beach | Caution advisory, last posted Jul 12, 2021. No all-clear recorded. |
| Silverwood Lake, outlet | The state's latest record, from Oct 30, 2020, recommends no advisory. |
| Silverwood Lake, Sawpit Swim Beach | The state's latest record, from Sep 3, 2020, recommends no advisory. |
| Silverwood Lake, Cleghorn Swim Beach | The state's latest record, from Sep 3, 2020, recommends no advisory. |
| Silverwood Lake, Live Oak | The state's latest record, from Jun 1, 2020, recommends no advisory. |
| Spot not described | Caution advisory, last posted Aug 11, 2017. No all-clear recorded. |
| Spot not described | Caution advisory, last posted Jun 12, 2017. No all-clear recorded. |
| Spot not described | The state's latest record, from Sep 20, 2016, recommends no advisory. |
Advisory history
Every advisory record the state has published for Silverwood 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 |
|---|---|---|---|
| Oct 19, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 19, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Oct 19, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 2, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Oct 2, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Oct 2, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 30, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 30, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 30, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 22, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 22, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 22, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 22, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 22, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 17, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 17, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 17, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 8, 2026 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Sep 8, 2026 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Sep 8, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 8, 2026 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Aug 24, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 24, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 24, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake outlet | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake outlet | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 7, 2026 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 31, 2026 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 31, 2026 | Silverwood Lake outlet | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 31, 2026 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 30, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Jul 30, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 30, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 15, 2026 | Silverwood Lake Sawpit Swim Beach | Danger | Updates from routine monitoring program-organization |
| Jul 15, 2026 | Silverwood Lake Cleghorn Swim Beach | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 15, 2026 | Silverwood Lake outlet | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 8, 2026 | Silverwood Lake Sawpit Swim Beach | Danger | Updates from routine monitoring program-organization |
| Jul 8, 2026 | Silverwood Lake Cleghorn Swim Beach | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 8, 2026 | Silverwood Lake outlet | Danger | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 2, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 2, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 2, 2026 | Silverwood Lake Sawpit Swim Beach | Danger | Updates from routine monitoring program-organization |
| Jun 25, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 25, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 25, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 12, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 12, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 12, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 9, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 9, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 9, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 29, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 29, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 29, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 22, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 22, 2026 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 22, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 22, 2026 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 22, 2026 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 14, 2025 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Sep 30, 2025 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Sep 16, 2025 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Sep 9, 2025 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Sep 9, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Sep 9, 2025 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Sep 2, 2025 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Sep 2, 2025 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 2, 2025 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 25, 2025 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 25, 2025 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Aug 25, 2025 | Silverwood Lake outlet | Warning | Updates from routine monitoring program-organization |
| Aug 25, 2025 | Silverwood Lake outlet | Warning | Updates from routine monitoring program-organization |
| Aug 20, 2025 | Silverwood Lake Sawpit Swim Beach | Warning | Updates from routine monitoring program-organization |
| Aug 20, 2025 | Silverwood Lake Cleghorn Swim Beach | Danger | Updates from routine monitoring program-organization |
| Aug 20, 2025 | Silverwood Lake outlet | Warning | Updates from routine monitoring program-organization |
| Aug 14, 2025 | Silverwood Lake Sawpit Swim Beach | Warning | Updates from routine monitoring program-organization |
| Aug 14, 2025 | Silverwood Lake outlet | Warning | Updates from routine monitoring program-organization |
| Aug 1, 2025 | Silverwood Lake Cleghorn Swim Beach | Danger | Updates from routine monitoring program-organization |
| Aug 1, 2025 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 1, 2025 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 1, 2025 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Jul 25, 2025 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Jul 25, 2025 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Jul 24, 2025 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Jul 24, 2025 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Jul 24, 2025 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Jul 24, 2025 | Silverwood Lake Cleghorn Swim Beach | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 24, 2025 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 21, 2025 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 21, 2025 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 21, 2025 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 1, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jul 1, 2025 | Silverwood Lake outlet | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jul 1, 2025 | Silverwood Lake Sawpit Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 26, 2025 | Silverwood Lake Sawpit Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 26, 2025 | Silverwood Lake Sawpit Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 26, 2025 | Silverwood Lake outlet | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 26, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 17, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 17, 2025 | Silverwood Lake outlet | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 17, 2025 | Silverwood Lake Sawpit Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 10, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 10, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 10, 2025 | Silverwood Lake outlet | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 3, 2025 | Silverwood Lake Sawpit Swim Beach | None | Testing results below posting triggers; Updates from routine monitoring program-organization |
| Jun 3, 2025 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 3, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 3, 2025 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| May 27, 2025 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| May 27, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| May 27, 2025 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| May 8, 2025 | Miller Canyon | None | Updates from routine monitoring program-organization |
| May 8, 2025 | Marina | None | Updates from routine monitoring program-organization |
| May 5, 2025 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| May 5, 2025 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| May 5, 2025 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Apr 25, 2025 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Oct 21, 2024 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Oct 21, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Oct 21, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization; Visual monitoring only-absent bloom |
| Oct 1, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Sep 17, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Sep 6, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Sep 6, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Sep 6, 2024 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Sep 6, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Aug 28, 2024 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Aug 28, 2024 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 28, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 21, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 21, 2024 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Aug 21, 2024 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 12, 2024 | Silverwood Lake Sawpit Swim Beach | Warning | Updates from routine monitoring program-organization |
| Aug 12, 2024 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Aug 12, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Aug 6, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 6, 2024 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 6, 2024 | Silverwood Lake outlet | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 30, 2024 | Silverwood Lake outlet | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 30, 2024 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 30, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 23, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 23, 2024 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 23, 2024 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 12, 2024 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 12, 2024 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 12, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 12, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Jul 12, 2024 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 12, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 5, 2024 | Willows cove | None | Floating/planktonic bloom observed; Updates from routine monitoring program-organization |
| Jul 5, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 5, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 5, 2024 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 28, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 28, 2024 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 28, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 25, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 25, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 25, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 25, 2024 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 14, 2024 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 14, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 14, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| Jun 12, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| Jun 12, 2024 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 12, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 4, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 4, 2024 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jun 4, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| May 28, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| May 28, 2024 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 28, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| May 13, 2024 | Silverwood Lake Sawpit Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 13, 2024 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| May 13, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| May 13, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| May 13, 2024 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| May 3, 2024 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| May 3, 2024 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization; Visual monitoring only-present bloom |
| Apr 30, 2024 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Dec 12, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Dec 12, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Dec 12, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Dec 12, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Nov 30, 2023 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Nov 30, 2023 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Nov 30, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Nov 30, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Nov 30, 2023 | Silverwood Lake Cleghorn Swim Beach | Caution | Updates from routine monitoring program-organization |
| Nov 9, 2023 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Nov 9, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Nov 9, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Oct 30, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Oct 30, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Oct 30, 2023 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Oct 23, 2023 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Oct 23, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Oct 23, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Oct 17, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Oct 17, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Oct 17, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Oct 9, 2023 | Silverwood Lake Cleghorn Swim Beach | Warning | Updates from routine monitoring program-organization |
| Oct 9, 2023 | Silverwood Lake Sawpit Swim Beach | Warning | Updates from routine monitoring program-organization |
| Oct 9, 2023 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Oct 3, 2023 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Oct 3, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Oct 3, 2023 | Silverwood Lake Cleghorn Swim Beach | Danger | Updates from routine monitoring program-organization |
| Sep 28, 2023 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 28, 2023 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 28, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 21, 2023 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 21, 2023 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 21, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 15, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 15, 2023 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 15, 2023 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 7, 2023 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 7, 2023 | Silverwood Lake Cleghorn Swim Beach | Danger | Updates from routine monitoring program-organization |
| Sep 7, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Sep 7, 2023 | Silverwood Lake Cleghorn Swim Beach | Danger | Updates from routine monitoring program-organization |
| Sep 5, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Updates from routine monitoring program-organization |
| Sep 5, 2023 | Silverwood Lake outlet | Caution | Updates from routine monitoring program-organization |
| Sep 5, 2023 | Silverwood Lake Cleghorn Swim Beach | Danger | Updates from routine monitoring program-organization |
| Aug 24, 2023 | Silverwood Lake Cleghorn Swim Beach | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 24, 2023 | Silverwood Lake outlet | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 24, 2023 | Silverwood Lake Sawpit Swim Beach | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 17, 2023 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 17, 2023 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 17, 2023 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 8, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 8, 2023 | Silverwood Lake outlet | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 8, 2023 | Silverwood Lake Cleghorn Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Aug 8, 2023 | Silverwood Lake Sawpit Swim Beach | Caution | Lake-wide advisory; Updates from routine monitoring program-organization |
| Jul 28, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 28, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 28, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 17, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 17, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 17, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 10, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 10, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 10, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 10, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 30, 2023 | Willows cove | None | Floating/planktonic bloom observed; Updates from routine monitoring program-organization |
| Jun 30, 2023 | Willows cove | Caution | Floating/planktonic bloom observed; Updates from routine monitoring program-organization |
| Jun 30, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 30, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 30, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 30, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 23, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 23, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 23, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 16, 2023 | Willows cove | Caution | Floating/planktonic bloom observed; Updates from routine monitoring program-organization |
| Jun 16, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 16, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 16, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 6, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 6, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 6, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| May 30, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| May 30, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| May 30, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| May 30, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| May 2, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jan 6, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jan 6, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jan 6, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jan 6, 2023 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jan 6, 2023 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jan 6, 2023 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Dec 15, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Dec 15, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Dec 15, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Dec 15, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Lake-wide advisory; Updates from routine monitoring program-organization |
| Dec 1, 2022 | Silverwood Lake Cleghorn Swim Beach | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 29, 2022 | Silverwood Lake Cleghorn Swim Beach | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Nov 29, 2022 | Silverwood Lake Cleghorn Swim Beach | Warning | Lake-wide advisory; Updates from routine monitoring program-organization |
| Oct 26, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Sep 14, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Aug 30, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 30, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 30, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 17, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Aug 11, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 11, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 11, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Aug 4, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 4, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Aug 4, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 27, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 27, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 27, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 21, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 8, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jul 8, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 21, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 21, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 21, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 16, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 16, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 16, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jun 3, 2022 | Silverwood Lake Sawpit Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 3, 2022 | Silverwood Lake Cleghorn Swim Beach | None | Updates from routine monitoring program-organization |
| Jun 3, 2022 | Silverwood Lake outlet | None | Updates from routine monitoring program-organization |
| Jul 12, 2021 | outlet | None | Testing results below posting triggers |
| Jul 12, 2021 | Cleghorn Swim Beach | Caution | Advisory based on visual and toxins |
| Jul 12, 2021 | Sawpit Swim Beach | Caution | Advisory based on visual and toxins |
| Oct 30, 2020 | Silverwood Lake, outlet | None | |
| Sep 3, 2020 | Silverwood Lake, Sawpit Swim Beach | None | |
| Sep 3, 2020 | Silverwood Lake, Cleghorn Swim Beach | None | |
| Jun 1, 2020 | Silverwood Lake, Live Oak | None | De-posting advisory. |
| Aug 11, 2017 | Spot not described | Caution | |
| Jun 12, 2017 | Spot not described | Caution | |
| Sep 20, 2016 | Spot not described | 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.