Lake Nagasawa: toxic algae advisories
Lake Nagasawa, Sonoma County. See all Sonoma County waters.
What the state's records say
Reports on file, with no advisory level the state has classified.
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 Lake Nagasawa
The state has reports on file for Lake Nagasawa but has not classified an advisory level, so the records cannot answer this. Keep your dog out of discolored or scummy water.
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 |
|---|---|
| Lakewide | Reports on file, with no advisory level the state has classified. |
Advisory history
Every advisory record the state has published for Lake Nagasawa, 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 |
|---|---|---|---|
| Jul 15, 2022 | Lakewide | NA - refer to Report Details | End date recorded: Dec 27, 2022. Under investigation |
| Jul 15, 2022 | Lakewide | NA - refer to Report Details | Under investigation |
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.