Rapid water quality and biodiversity assessment of Hennagara Lake, Bengaluru



An assessment of the baseline condition of Hennagara Lake – an artificial tank located in Anekal Taluk, Bengaluru Urban district, Karnataka, was conducted from April to June 2022. The aim of the study was to develop a comprehensive road map for the restoration and sustainability of Hennagara Lake. The study comprised an evaluation of the lake water quality and hydrology, an examination of human-lake interactions and an assessment of biodiversity in and around the lake area. Further, the study intended to understand the needs of the local stakeholders regarding water use as a prerequisite to setting up realistic goals for its restoration. The performance of lake restoration projects is evaluated by a universal measure, i.e., attaining Class B of the Designated Best Use Water Quality Criteria, published by the Central Pollution Control Board. The proposed approach attempts to shift the focus of evaluation to one based on current and anticipated uses of the lake water and associated water quality targets required for restoration in an iterative manner.

After consulting with stakeholders and engaging with the local communities, we recommend that the lake restoration be aimed towards attaining and sustaining Class D Water Quality Criteria, which specifies that the lake should be aesthetically pleasing and fit for fisheries and irrigation for present and future generations. Given the increase in population around the lake and the rise of apartment buildings in its surroundings, local communities heavily advocate tourism and recreation in the lake, adding to the goals of the restoration. Stakeholder engagement and further discussions with polluters and the concerned government authorities are considered imperative to remedy the current state of the lake.