The dam's primary core is made of earth and rocks, making it an 'earthen' dam rather than a concrete gravity structure.
The reservoir area covers approximately 12.77 square kilometers at full capacity.
The submerged hillocks in the reservoir appear as islands, locally referred to as 'Banasura Sagar Islands'.
The dam was named after Banasura, a mythological king who, according to local legend, performed penance in the surrounding hills.
The reservoir is a primary water catchment area for the Kabini river system in the Cauvery basin.
The site remains a focal point for studies on ecological preservation in the Western Ghats biodiversity hotspot.
Banasura Sagar Dam is the largest earthen dam in India and the second-largest in Asia, located in the Wayanad district of Kerala. The dam was constructed as part of the Banasurasagar Project to support the Kakkayam Hydroelectric power project. It impounds the waters of the Karamanathodu river, a tributary of the Kabini River. The reservoir features a cluster of small islands formed by submerged hillocks that become visible when water levels recede. The dam structure is composed of massive stacks of boulders and stones. It sits at the foothills of the Banasura hills, which reach an elevation of approximately 2,073 meters. The site serves as a primary source of irrigation and drinking water for the surrounding region. The surrounding landscape consists of undulating grasslands and dense tropical forests.
The crest of the dam provides a panoramic 360-degree view of the reservoir islands and the surrounding mountain ranges.
Bring a windbreaker or light jacket as the hilltop can become windy and chilly.
Visit the boating area early in the day to avoid the peak crowds that arrive by midday.
Carry binoculars to spot wildlife and diverse bird species across the reservoir.
Do not attempt to swim in the reservoir, as the water is deep and the bottom is uneven due to submerged terrain.
Maintain silence near the water's edge and carry all plastic waste back with you to preserve the reservoir's cleanliness.
