National Authority
for the Litani River
National Authority for the Litani River

Why did the lake become green?

04 October 2023

Water is usually affected by several factors that lead to changing its color and smell. In the summer or when the temperature rises, the color of the water in Lake Qaraoun changes to become green. The most prominent reasons that lead to this are:

Climate change and temperature rate:
The climate in general has an effect on the color of the water, as it varies according to temperature, and ranges from blue to green as it rises. Loss of ecosystem health in lake water may also lead to a shift in color.

Cyanobacteria:
Bacteria that live in water, become more active and float to the surface as temperatures rise. Therefore, the green color increases in the summer as a result of the reproduction of these types of bacteria, which are also called “blue-green algae.”