Reservoir · Amador County · CA
Is Lower Bear River Reservoir safe to swim?
No advisory or algae bloom reported for this water today.
Updated August 20, 2026 · EPA CyAN satellite
No bacteria advisory or sampling for this water.
No blue-green algae bloom detected in the latest clear satellite image. This is a satellite estimate, not a safety guarantee, and does not replace an official advisory.
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Lower Bear River Reservoir is clear today. Be the first to know when it's not.
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What's in the water at Lower Bear River Reservoir right now
As of August 20, 2026, Lower Bear River Reservoir in Amador County, California has no advisory posted. EPA's CyAN satellite detected no blue-green algae bloom in the latest clear image (August 19, 2026), which is an estimate, not a guarantee. Modeled rainfall over the past week was about 0.0 in (Open-Meteo, a gridded estimate that can differ from a local gauge), which can wash bacteria and nutrients into the water.
Blue-green algae at Lower Bear River Reservoir
Lower Bear River Reservoir is a reservoir in Amador County, California covering about 1.1 sq mi, the 113th-largest of the 186 lakes SwimZone monitors in California. EPA's CyAN satellite detected no blue-green algae bloom in the latest clear image (August 19, 2026), which is an estimate, not a guarantee.
Blue-green algae (cyanobacteria) blooms are most common from midsummer into early fall, when the water is warm, calm, and rich in nutrients from runoff. They can produce toxins that make people sick and can be rapidly fatal to dogs, so skip water that looks green, scummy, or like spilled paint, and keep children and pets out of it.
Bloom history at Lower Bear River Reservoir
From EPA CyAN's satellite archive
Each bar is that summer's peak EPA CyAN satellite estimate (log scale); the red cap is the part above the bloom-level threshold. Satellite estimates, not water samples or posted advisories.
Over 7 summers of EPA CyAN satellite imagery since 2020, Lower Bear River Reservoir has not shown a satellite-estimated bloom-level signal. This is an estimate, not a guarantee, and conditions can change quickly, so check the current read and official advisories before you swim.
When to swim at Lower Bear River Reservoir
It is currently peak season for blue-green algae, when warm, calm water lets blooms form fastest. This water has no recorded advisory-level bloom in its satellite history, which makes it a comparatively steady summer swim spot; conditions still change between samples, so check the current read before you go.
Frequently asked: swimming in Lower Bear River Reservoir
- Is it safe to swim in Lower Bear River Reservoir right now?
- Lower Bear River Reservoir has no advisory posted today. EPA's CyAN satellite detected no blue-green algae bloom in the latest clear image (August 19, 2026), which is an estimate, not a guarantee. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
- Does Lower Bear River Reservoir have blue-green algae (cyanobacteria)?
- EPA's CyAN satellite detected no blue-green algae bloom at Lower Bear River Reservoir in the latest clear image (August 19, 2026). This is a satellite estimate below the sensor's detection limit, not a guarantee: cyanobacteria can appear within hours in warm, calm, nutrient-rich water, so look before you swim.
- Can dogs swim in Lower Bear River Reservoir?
- No bloom is detected at Lower Bear River Reservoir today, but dogs are much more vulnerable to blue-green algae than people, and blooms can form within hours. Always keep dogs away from water that looks green, scummy, or discolored, and rinse them off after swimming.
- How often does Lower Bear River Reservoir have blue-green algae blooms?
- Over 7 summers of EPA CyAN satellite imagery since 2020, Lower Bear River Reservoir has not shown a satellite-estimated bloom-level signal. This is an estimate, not a guarantee, and conditions can change quickly, so check the current read and official advisories before you swim.
- How many California lakes and beaches are unsafe for swimming today?
- Today, 0 California waters are above a safe-contact threshold and 21 more warrant caution, out of 445 monitored waters SwimZone tracks in the state.
- How is Lower Bear River Reservoir's water quality measured?
- SwimZone builds this read from EPA CyAN satellite imagery for blue-green algae, official beach and fecal-bacteria advisories where a program monitors Lower Bear River Reservoir, and a recent-rainfall overlay, all refreshed daily. It was last updated August 20, 2026.
Before you swim: the basics
Swim spots near Lower Bear River Reservoir
All California →All 6 monitored waters nearest Lower Bear River Reservoir are clear today.
| Water | Distance | Today | Algae read | Sampled |
|---|---|---|---|---|
| Salt Springs ReservoirReservoir · Amador County | 4.5 mi | No advisory | None detected | Aug 19 |
| Silver LakeLake · Amador County | 10 mi | No advisory | None detected | Aug 19 |
| Caples LakeLake · Alpine County | 15 mi | No advisory | None detected | Aug 19 |
| Upper Blue LakeLake · Alpine County | 17 mi | No advisory | None detected | Aug 19 |
| Spicer Meadow ReservoirReservoir · Alpine County | 18 mi | No advisory | None detected | Aug 19 |
| Ice House ReservoirReservoir · El Dorado County | 20 mi | No advisory | None detected | Aug 19 |