Reservoir · Rio Arriba County · NM
Is El Vado Reservoir safe to swim?
Blue-green algae is above the safe-contact threshold.
Updated July 20, 2026 · EPA CyAN satellite
SwimZone for iPhone · launching soon
Know before you get in at El Vado Reservoir.
Get an alert the day a bacteria or algae advisory goes up.
What's in the water at El Vado Reservoir right now
As of July 20, 2026, El Vado Reservoir in Rio Arriba County, New Mexico is not recommended for swimming. Satellite imagery measured 135,277 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold. Rainfall over the past week totaled 0.0 in, which can wash bacteria and nutrients into the water.
Blue-green algae at El Vado Reservoir
El Vado Reservoir is a reservoir in Rio Arriba County, New Mexico covering about 4.9 sq mi, the 6th-largest of the 24 lakes SwimZone monitors in New Mexico. Satellite imagery measured 135,277 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold.
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 El Vado Reservoir
From EPA CyAN's satellite archive
Over 7 summers of satellite monitoring since 2020, El Vado Reservoir has reached blue-green algae advisory levels in 1 of them, most recently in July 2026. Blooms here have been occasional rather than annual. Its highest recorded reading was 344,971 cells/mL in July 2026.
Frequently asked: swimming in El Vado Reservoir
- Is it safe to swim in El Vado Reservoir right now?
- El Vado Reservoir is not recommended for swimming today. Satellite imagery measured 135,277 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
- Does El Vado Reservoir have blue-green algae (cyanobacteria)?
- Yes. Satellite monitoring measured 135,277 cells/mL of blue-green algae (cyanobacteria) at El Vado Reservoir on July 19, 2026, above the 100,000 cells/mL advisory level. Avoid swimming and keep children and pets out of the water.
- Can dogs swim in El Vado Reservoir?
- No. Blue-green algae at El Vado Reservoir is above the safe-contact threshold (135,277 cells/mL on July 19, 2026). Cyanobacteria toxins can be rapidly fatal to dogs, which swallow it while swimming and lick it from their fur. Keep dogs out of the water and away from any scum along the shore.
- How often does El Vado Reservoir have blue-green algae blooms?
- Over 7 summers of satellite monitoring since 2020, El Vado Reservoir has reached blue-green algae advisory levels in 1 of them, most recently in July 2026. Blooms here have been occasional rather than annual. Its highest recorded reading was 344,971 cells/mL in July 2026.
- How many New Mexico lakes and beaches are unsafe for swimming today?
- Today, 4 New Mexico waters are above a safe-contact threshold and 0 more warrant caution, out of 27 monitored waters SwimZone tracks in the state.
- How is El Vado 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 El Vado Reservoir, and a recent-rainfall overlay, all refreshed daily. It was last updated July 20, 2026.