Is Kanopolis Lake safe to swim?

As of July 20, 2026, Kanopolis Lake in Ellsworth County, Kansas is not recommended for swimming. Satellite imagery measured 252,501 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.

How this read is built

Kanopolis Lake is a lake in Ellsworth County, Kansas covering about 5.4 sq mi, the 12th-largest of the 28 lakes SwimZone monitors in Kansas. Satellite imagery measured 252,501 cells/mL of blue-green algae on July 19, 2026, above the 100,000 cells/mL advisory threshold. Larger, warmer waters like this can hold a bloom for weeks once nutrients and calm weather line up.

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.

Over 7 summers of satellite monitoring since 2020, Kanopolis Lake has reached blue-green algae advisory levels in 4 of them, most recently in July 2025. Its highest recorded reading was 527,938 cells/mL in June 2020.

Is it safe to swim in Kanopolis Lake right now?

Kanopolis Lake is not recommended for swimming today. Satellite imagery measured 252,501 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 Kanopolis Lake have blue-green algae (cyanobacteria)?

Yes. Satellite monitoring measured 252,501 cells/mL of blue-green algae (cyanobacteria) at Kanopolis Lake 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 Kanopolis Lake?

No. Blue-green algae at Kanopolis Lake is above the safe-contact threshold (252,501 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 Kanopolis Lake have blue-green algae blooms?

Over 7 summers of satellite monitoring since 2020, Kanopolis Lake has reached blue-green algae advisory levels in 4 of them, most recently in July 2025. Its highest recorded reading was 527,938 cells/mL in June 2020.

How many Kansas lakes and beaches are unsafe for swimming today?

Today, 10 Kansas waters are above a safe-contact threshold and 1 more warrant caution, out of 30 monitored waters SwimZone tracks in the state.

How is Kanopolis 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 Kanopolis Lake, and a recent-rainfall overlay, all refreshed daily. It was last updated July 20, 2026.