Reservoir · Twin Falls County · ID
Is Salmon Falls Creek Reservoir safe to swim?
No advisory or algae bloom reported for this water today.
Updated July 20, 2026 · EPA CyAN satellite
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What's in the water at Salmon Falls Creek Reservoir right now
As of July 20, 2026, Salmon Falls Creek Reservoir in Twin Falls County, Idaho is clear to swim. Satellite imagery detected no blue-green algae bloom as of July 19, 2026. Rainfall over the past week totaled 0.0 in, which can wash bacteria and nutrients into the water.
Blue-green algae at Salmon Falls Creek Reservoir
Salmon Falls Creek Reservoir is a reservoir in Twin Falls County, Idaho covering about 4.5 sq mi, the 20th-largest of the 63 lakes SwimZone monitors in Idaho. Satellite imagery detected no blue-green algae bloom as of July 19, 2026.
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 Salmon Falls Creek Reservoir
From EPA CyAN's satellite archive
Over 7 summers of satellite monitoring since 2020, Salmon Falls Creek Reservoir has reached blue-green algae advisory levels in 7 of them, most recently in July 2026. This is a lake that blooms most summers. Its highest recorded reading was 1,346,304 cells/mL in August 2023.
Frequently asked: swimming in Salmon Falls Creek Reservoir
- Is it safe to swim in Salmon Falls Creek Reservoir right now?
- Salmon Falls Creek Reservoir is clear to swim today. Satellite imagery detected no blue-green algae bloom as of July 19, 2026. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
- Does Salmon Falls Creek Reservoir have blue-green algae (cyanobacteria)?
- No blue-green algae bloom is detectable at Salmon Falls Creek Reservoir as of July 19, 2026 (below the satellite's roughly 10,000 cells/mL detection limit). Cyanobacteria can still appear within hours in warm, calm, nutrient-rich water, so look before you swim.
- Can dogs swim in Salmon Falls Creek Reservoir?
- No bloom is detected at Salmon Falls Creek 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 Salmon Falls Creek Reservoir have blue-green algae blooms?
- Over 7 summers of satellite monitoring since 2020, Salmon Falls Creek Reservoir has reached blue-green algae advisory levels in 7 of them, most recently in July 2026. This is a lake that blooms most summers. Its highest recorded reading was 1,346,304 cells/mL in August 2023.
- How many Idaho lakes and beaches are unsafe for swimming today?
- Today, 9 Idaho waters are above a safe-contact threshold and 1 more warrant caution, out of 66 monitored waters SwimZone tracks in the state.
- How is Salmon Falls Creek 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 Salmon Falls Creek Reservoir, and a recent-rainfall overlay, all refreshed daily. It was last updated July 20, 2026.