Is Colonial Pond safe to swim?

As of July 20, 2026, Colonial Pond in Fulton County, Indiana is not recommended for swimming. Satellite imagery measured 471,306 cells/mL of blue-green algae on July 18, 2026, above the 100,000 cells/mL advisory threshold. Rainfall over the past week totaled 1.4 in, which can wash bacteria and nutrients into the water.

How this read is built

Colonial Pond is a pond in Fulton County, Indiana covering about 1.3 sq mi, the 23rd-largest of the 53 lakes SwimZone monitors in Indiana. Satellite imagery measured 471,306 cells/mL of blue-green algae on July 18, 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.

Over 7 summers of satellite monitoring since 2020, Colonial Pond has reached blue-green algae advisory levels in 6 of them, most recently in June 2025. This is a lake that blooms most summers. Its highest recorded reading was 1,642,037 cells/mL in July 2024.

Is it safe to swim in Colonial Pond right now?

Colonial Pond is not recommended for swimming today. Satellite imagery measured 471,306 cells/mL of blue-green algae on July 18, 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 Colonial Pond have blue-green algae (cyanobacteria)?

Yes. Satellite monitoring measured 471,306 cells/mL of blue-green algae (cyanobacteria) at Colonial Pond on July 18, 2026, above the 100,000 cells/mL advisory level. Avoid swimming and keep children and pets out of the water.

Can dogs swim in Colonial Pond?

No. Blue-green algae at Colonial Pond is above the safe-contact threshold (471,306 cells/mL on July 18, 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 Colonial Pond have blue-green algae blooms?

Over 7 summers of satellite monitoring since 2020, Colonial Pond has reached blue-green algae advisory levels in 6 of them, most recently in June 2025. This is a lake that blooms most summers. Its highest recorded reading was 1,642,037 cells/mL in July 2024.

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

Today, 20 Indiana waters are above a safe-contact threshold and 5 more warrant caution, out of 81 monitored waters SwimZone tracks in the state.

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