Public Notices, Project Updates, and Alerts

May 14, 2019

Elevated Recreational Public Health Advisory Issued for Chippewa Lake

Water samples collected on May 14 show toxin levels of 21.8 parts per billion due to a harmful algal bloom. Because the toxin level currently exceeds 20 ppb, Chippewa Lake will remain open to boaters on an idle-speed, no-wake basis only. All persons should avoid all contact with the water -- including activities such as swimming, jet-skiing, and water skiing. Warning flags at the public boat launch ramp on Westfield Landing Road have been raised to alert boaters and swimmers of the harmful algal blooms. Two warning flags will be flown. The yellow flag indicates boating permitted on an idle-speed, no-wake basis. The red flag warns the public to avoid contact with the water.

Algal blooms occur due to a combination of factors including water temperature, rainfall, and nutrient runoff within the watershed. The Chippewa Lake algal bloom is the result of a microscopic organism called cyanobacteria. Its blooms can produce harmful toxins that may make people and pets sick when they come into contact with the water.

Per Ohio’s Harmful Algal Bloom Response Strategy for Recreational Waters, a Recreational Public Health Advisory is issued when toxin levels reach 6 ppb. It warns children, pregnant or nursing women, individuals with certain medical conditions, and pets to avoid contact with the water. When toxin levels reach 20 ppb, an Elevated Recreational Public Health Advisory is issued, warning all persons and pets to avoid all contact with the water. The warnings remain in effect until two consecutive tests taken at least one week apart show levels have dropped below those thresholds. The park district will continue to monitor toxin levels as needed.

2019 Test Results

May 14: 21.8 ppb--Elevated Recreational Health Advisory Issued
May 7:
17.8 ppb--Recreational Public Health Advisory Remains
April 30: 9.49 ppb--Recreational Public Health Advisory Issued
April 22 5.74 ppb--No advisories in place
March 19: <0.14 ppb--No advisories in place
February 19: <0.14 ppb--No advisories in place
January 22: <0.14 ppb--No advisories in place


Warning Flag System in Place at Chippewa Lake

The warning flag system alerts boaters and swimmers to water conditions at Chippewa Lake due to harmful algal blooms or other safety concerns.

Color keys explain what each flag means:

Green -- Lake open

Yellow -- Boating permitted at idle speed only

Orange -- Warning: Algal toxins present

Red -- Danger: Avoid contact with the water


CL flag color graphic without black