Last year, nearly 400,000 residents in and around Toledo did not have their water supply for three days in August because of a bloom of toxic blue-green algae in Lake Erie. Now researchers in a new report have issued warning saying that Lake Erie might have one of the biggest algae blooms in recent years.

Report from the National Oceanographic and Atmospheric Administration (NOAA) found that heavy rains throughout the month of June can be the reason for the largest bloom of harmful algae in the Great Lake.

A record-setting event in 2011 covered 2, 000 square miles of water in swirling green alage, said researchers.

Richard Stumpf, an oceanographer with NOAA's National Centers for Coastal Science, said in a statement that the forecast given in the report allows all those who need to plan to have advance warning.

The warnings highlighted in the reports cautions cities that they can start preparations of water treatment and organizations that monitor lake quality can be at the ready.

According to researchers, the cyanobacterial algae found in Lake Erie can decimate fish populations by consuming oxygen in the water and creating so-called dead zones.

The cyanobacterial algae can also produce toxins that are harmful to humans. Experts recommend restricting access to swimming and other lake activities, and requiring drinking water to be treated and filtered.

Blooms are common in August and September, said experts. NOAA measures the severity of algae bloom on a 10-point scale.

Last year's algae bloom measured 6.5 on the index, which was high enough to contaminate the drinking water of 400,000 people in Toledo.