About Kolleru lake

• It is a natural eutrophic lake (a lake with high productivity, high nutrients and with dark water. The water is usually not good for drinking purpose) in Andhra Pradesh, situated between the two major river basins of the Godavari and the Krishna, fed by two seasonal rivers and a number of drains and channels, which functions as a natural flood balancing reservoir between the deltas of the two rivers. 
• It provides habitat for a number of resident and migratory birds, including declining numbers of the vulnerable Grey Pelican (Pelecanus philippensis), and sustains both culture and capture fisheries, agriculture and related occupations of the people in the area. 

Why in the news?

• Kolleru lake has become a tourist attraction after the recovery due to heavy rains recently.
• It has revived fish populations and helped the localities revive their occupations.

References:

1. https://www.easybiologyclass.com/difference-between-oligotrophic-and-eutrophic-lakes/
2. https://rsis.ramsar.org/ris/1209
3. https://indibuzzonline.com/india/brimming-kolleru-beckons-nature-lovers/