Dodge Reservoir: toxic algae advisories
Dodge Reservoir, Lassen County. See all Lassen County waters.
What the state's records say
Visual observation, last posted Jul 31, 2026. 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: The state recorded an advisory of a type outside the Caution, Warning and Danger levels. Read the sign posted at the water.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Dodge Reservoir
The state has an advisory on file for Dodge Reservoir (Visual observation), last posted Jul 31, 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 Jan 17, 2026: about 11,000 cells/mL of cyanobacteria near the center of Dodge Reservoir.
A satellite estimate from EPA CyAN for a 1.2 km² lake. It does not measure toxins and does not change the advisory status.
| Week ending | Estimate |
|---|---|
| Jan 17, 2026 | about 11,000 cells/mL |
| Oct 4, 2025 | about 110,000 cells/mL |
| Sep 27, 2025 | about 570,000 cells/mL |
| Sep 20, 2025 | about 1,100,000 cells/mL |
| Sep 13, 2025 | about 910,000 cells/mL |
| Sep 6, 2025 | about 690,000 cells/mL |
| Aug 30, 2025 | about 690,000 cells/mL |
| Aug 23, 2025 | about 470,000 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 |
|---|---|
| Campground | Visual observation, last posted Jul 31, 2026. No all-clear recorded. |
Advisory history
Every advisory record the state has published for Dodge 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 |
|---|---|---|---|
| Jul 31, 2026 | Campground | Visual observation | Suspected bloom, investigation ongoing |
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.