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) 


                                     To report potential HAB-related illnesses, please contact

                                             the Poison Control Center at 1-800-222-1222

Harmful Algal Bloom (HAB) Conditions

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

The following is a summary of the Louisville District's HAB Response in FY16.


At the conclusion of FY16 HAB sampling season (May-September), Brookville, Harden, Roush, Salamonie, Mississinewa, and Monroe reservoirs were still experiencing HABs. In accordance with the agreement with the Indiana state agencies, HAB Response in Indiana is hereby suspended until May 2017.



Nolin reservoir was initially investigated for a HAB after results from a independent study found microcystin on 8/19  at 39.3 ug/L. The KDOW re-sampled the site on 8/30 and found no detectable amounts of microcystin and concluded that no HAB was present.  An illness complaint received 8/31 prompted the KDOW to request LRL's assistance in collecting additional HAB samples on 9/6. The results from those test found no detectable amounts of microcystin and the KDOW concluded that no HAB was present.



Harsha reservoir experienced a HAB from 6/10 through 7/14. CJ Brown reservoir personnel filed a Bloom Report with the OEPA on 9/22, fulfilling the district's responsibility under the Final Agreement with the Ohio state agencies; the OEPA responded on 10/3 notifying the district that they would collect HAB samples if visual HAB indicators were observed at the boat ramps or beaches.


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