Lake · Stevens County · MN

Is Pomme de Terre Lakes safe to swim?

Use caution

Satellite imagery suggests a possible blue-green algae bloom; check local advisories.

Updated August 20, 2026 · EPA CyAN satellite

Recent rain (modeled)
0.0 in
Water type
Lake
Last updated
Aug 20
Bacteria
E. coli, fecal
Not monitored
Tested
Not monitored

No bacteria advisory or sampling for this water.

Blue-green algae
cyanobacteria
Use caution
Tested
Possible bloom
Advisory over
100,000
cells/mL

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.

Satellite estimate · imaged Aug 19 · EPA CyAN satellite · moderate confidence
An estimate from EPA CyAN satellite imagery, not a water sample or an official advisory. Check your state or county health department for the official status. Report a data question.

SwimZone for iPhone · launching soon

Conditions at Pomme de Terre Lakes 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 Pomme de Terre Lakes right now

As of August 20, 2026, Pomme de Terre Lakes in Stevens County, Minnesota 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.

How this read is built

Blue-green algae at Pomme de Terre Lakes

Pomme de Terre Lakes is a lake in Stevens County, Minnesota. 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 Pomme de Terre Lakes

From EPA CyAN's satellite archive

2020: peak satellite estimate about 450,000 cells/mL, above the ~100k bloom-level threshold202021: peak satellite estimate about 1,500,000 cells/mL, above the ~100k bloom-level threshold212022: peak satellite estimate about 930,000 cells/mL, above the ~100k bloom-level threshold222023: peak satellite estimate about 1,500,000 cells/mL, above the ~100k bloom-level threshold232024: peak satellite estimate about 1,300,000 cells/mL, above the ~100k bloom-level threshold242025: peak satellite estimate about 1,400,000 cells/mL, above the ~100k bloom-level threshold252026: peak satellite estimate about 2,700,000 cells/mL, above the ~100k bloom-level threshold26Bloom level~100k cells/mL

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, Pomme de Terre Lakes 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 2,700,000 cells/mL in July 2026. These are satellite estimates, not water samples or posted advisories; check your state or county health department for official status.

When to swim at Pomme de Terre Lakes

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 July. 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 Pomme de Terre Lakes

Is it safe to swim in Pomme de Terre Lakes right now?
Pomme de Terre Lakes 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 Pomme de Terre Lakes have blue-green algae (cyanobacteria)?
Possibly. EPA's CyAN satellite estimated a possible blue-green algae bloom at Pomme de Terre Lakes 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 Pomme de Terre Lakes?
Use caution. EPA's CyAN satellite estimated elevated blue-green algae at Pomme de Terre Lakes 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 Pomme de Terre Lakes have blue-green algae blooms?
Over 7 summers of EPA CyAN satellite imagery since 2020, Pomme de Terre Lakes 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 2,700,000 cells/mL in July 2026. These are satellite estimates, not water samples or posted advisories; check your state or county health department for official status.
How many Minnesota lakes and beaches are unsafe for swimming today?
Today, 0 Minnesota waters are above a safe-contact threshold and 451 more warrant caution, out of 1178 monitored waters SwimZone tracks in the state.
How is Pomme de Terre Lakes'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 Pomme de Terre Lakes, and a recent-rainfall overlay, all refreshed daily. It was last updated August 20, 2026.

Before you swim: the basics

Swim spots near Pomme de Terre Lakes

All Minnesota

Of the 6 monitored waters nearest Pomme de Terre Lakes, 5 are flagged today.

WaterDistanceTodayAlgae readSampled
North Pomme de Terre LakeLake · Stevens County1.8 miNo advisoryNone detectedAug 19
Wintermute LakeLake · Stevens County3.8 miUse cautionUnconfirmedAug 19
Patchen LakeLake · Grant County5.2 miUse cautionUnconfirmedAug 19
Harstad SloughLake · Stevens County6.4 miUse cautionPossible bloomAug 19
Lake CharlotteLake · Stevens County7.2 miUse cautionPossible bloomAug 19
Lake CyrusLake · Stevens County8.5 miUse cautionUnconfirmedAug 19