Harmful Algal Bloom (HAB) Contact Info

To report signs of a potential HAB, please contact the following appropriate authority:

Kentucky, please call 502-564-3410 for the Kentucky Division of Water

Indiana, please call 1-800-451-6027 ext. 24464 for the Indiana Department of Environmental Management

Ohio, please call 614-644-2160 for the Ohio Environmental Protection Agency

Ohio River, please call 513-231-7719 for the Ohio River Sanitation Commission (ORSANCO) 

Harmful Algal Bloom (HAB) Conditions

The Louisville District HAB Response sampling has ceased until May 2016.

To request HAB data please contact the Louisville District Water Quality Team by calling 502-315-3217 or emailing louisvillewaterquality@usace.army.mil.

Please select the appropriate link below for specific area information.




Ohio River

Cyanobacteria Threshold Values

The Louisville District HAB Response Plans in the states of Ohio, Indiana and Kentucky are coordinated with and operate under the direction of the state agencies in each jurisdiction. In recognizing the state agencies as the water quality authorities, the Louisville District supports their determinations for and adoption of cyanobacteria threshold values. The Corps-operated reservoirs within each state are sampled for HABs in accordance with and in support of the final agreements and/or developing agreements with the respective state agencies.

For information about cyanobacteria thresholds in each state, please use the links provided for each state.

About Harmful Algal Blooms (HABs)

What are harmful algal blooms?

Freshwater harmful algal blooms (HABs) are significant and excessive growths of blue-green algae, also known as cyanobacteria. All freshwater lakes inhabit native blue-green algae species that are capable of producing HABs. Several of these species can at times produce toxins (called cyanotoxins) that are harmful to the nervous system (neurotoxins), the liver (hepatotoxins), and the skin (dermatoxins) of humans and other animals. In addition to cyanotoxins, HABs are can be harmful to the lake ecosystem, causing depletion of oxygen levels which can create fish kills.

What causes HABs to form?

General contributing factors that promote the formation of HABs are:

- Ample/excessive sunlight        - Low-water or low-flow conditions

- Warm temperatures                - Excessive nutrients (nitrogen & phosphorus)

Although some HABs occur during the cold seasons, they more frequently occur during the summer, when temperatures are high, sunlight is ample, and the flow of incoming water is low. Also, one of the most influential factors of HAB growth is the concentration of nutrients such as nitrogen and phosphorus. Nitrogen and phosphorus are both required by blue-green algae to live and are often scarce in the environment, therefore limiting growth. Most nitrogen and phosphorus pollution (also known as nutrient overloading) comes from the runoff of agricultural fertilizer, lawn fertilizer, untreated human sewage (storm overflows), and untreated animal sewage from concentrated animal feeding operations.

Additional HAB Information

For more information about HABs in the Louisville District, including information about state-coordinated HAB response plans or to request HAB data, please call 502-315-3217 or email the Louisville District Water Quality Team at louisvillewaterquality@usace.army.mil.


NOTICE: All data contained herein is preliminary in nature and therefore subject to change. The data is for general information purposes ONLY and SHALL NOT be used in technical applications such as, but not limited to, studies or designs. All critical data should be obtained from and verified by the United States Army Corps of Engineers, Louisville District, Water Quality Team, 600 Dr. Martin Luther King Jr. Place, Louisville, KY 40202. The United States of America assumes no liability for the completeness or accuracy of the data contained herein and any use of such data inconsistent with this disclaimer shall be solely at the risk of the user.

Water Quality

HAB Photos