Lake · Madera County · CA
Is H. V. Eastman Lake safe to swim?
Satellite imagery suggests a possible blue-green algae bloom; check local advisories.
Updated August 20, 2026 · EPA CyAN satellite
No bacteria advisory or sampling for this water.
EPA's CyAN satellite estimated a possible blue-green algae bloom here. This is a satellite estimate, not a water sample or an official advisory. Avoid contact with discolored or scummy water and check your state or county health department.
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Conditions at H. V. Eastman Lake are borderline right now.
Get a push the moment it tips into an advisory, and again the day it clears.
What's in the water at H. V. Eastman Lake right now
As of August 20, 2026, H. V. Eastman Lake in Madera County, California carries a swim caution. EPA's CyAN satellite estimated a possible blue-green algae bloom here (August 19, 2026); this is a satellite estimate, not a water sample or an official advisory. 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 H. V. Eastman Lake
H. V. Eastman Lake is a lake in Madera County, California covering about 1.6 sq mi, the 83rd-largest of the 186 lakes SwimZone monitors in California. EPA's CyAN satellite estimated a possible blue-green algae bloom here (August 19, 2026); this is a satellite estimate, not a water sample or an official advisory.
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 H. V. Eastman Lake
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, H. V. Eastman Lake has shown a satellite-estimated bloom-level signal in 7 of them, most recently in July 2026. It shows a bloom-level signal most summers. Its highest satellite estimate was about 2,100,000 cells/mL in August 2025. These are satellite estimates, not water samples or posted advisories; check your state or county health department for official status.
When to swim at H. V. Eastman Lake
It is currently peak season for blue-green algae, when warm, calm water lets blooms form fastest. This lake has bloomed in most monitored summers (7 of 7), historically peaking around August. Early summer, before the water fully warms, has generally been the safer window here; check the current read before you go either way.
Frequently asked: swimming in H. V. Eastman Lake
- Is it safe to swim in H. V. Eastman Lake right now?
- H. V. Eastman Lake carries a swim caution today. EPA's CyAN satellite estimated a possible blue-green algae bloom here (August 19, 2026); this is a satellite estimate, not a water sample or an official advisory. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
- Does H. V. Eastman Lake have blue-green algae (cyanobacteria)?
- Possibly. EPA's CyAN satellite estimated a possible blue-green algae bloom at H. V. Eastman Lake on August 19, 2026. This is a satellite estimate, not a water sample or an official advisory, so treat it as a reason to be careful: avoid discolored or scummy water and check your state or county health department for the official status.
- Can dogs swim in H. V. Eastman Lake?
- Use caution. EPA's CyAN satellite estimated elevated blue-green algae at H. V. Eastman Lake on August 19, 2026 (a satellite estimate, not confirmed by sampling). Dogs are far more sensitive to cyanobacteria than people, so keep them out of the water and away from surface scum, and check local advisories.
- How often does H. V. Eastman Lake have blue-green algae blooms?
- Over 7 summers of EPA CyAN satellite imagery since 2020, H. V. Eastman Lake has shown a satellite-estimated bloom-level signal in 7 of them, most recently in July 2026. It shows a bloom-level signal most summers. Its highest satellite estimate was about 2,100,000 cells/mL in August 2025. These are satellite estimates, not water samples or posted advisories; check your state or county health department for official status.
- 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 H. V. Eastman Lake'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 H. V. Eastman Lake, and a recent-rainfall overlay, all refreshed daily. It was last updated August 20, 2026.
Before you swim: the basics
Swim spots near H. V. Eastman Lake
All California →Of the 6 monitored waters nearest H. V. Eastman Lake, 1 is flagged today.
| Water | Distance | Today | Algae read | Sampled |
|---|---|---|---|---|
| Hensley LakeLake · Madera County | 9.0 mi | Use caution | Possible bloom | Aug 19 |
| Millerton LakeLake · Madera County | 22 mi | No advisory | None detected | Aug 19 |
| Bass LakeLake · Madera County | 24 mi | No advisory | None detected | Aug 19 |
| Yosemite LakeLake · Merced County | 27 mi | No advisory | None detected | Aug 19 |
| Lake McClureLake · Mariposa County | 32 mi | No advisory | None detected | Jul 21 |
| Mammoth Pool ReservoirReservoir · Madera County | 37 mi | No advisory | None detected | Jul 21 |