The Western Ghats is one among the 34 global hotspots of biodiversity and it lies in the western part of peninsular India in a series of hills stretching over a distance of 1,600 km from north to south and covering an area of about 1,60,000 sq.km.  It harbours very rich flora and fauna and there are records of over 4,000 species of flowering plants with 38% endemics, 330 butterflies with 11% endemics, 156 reptiles with 62% endemics, 508 birds with 4% endemics, 120 mammals with 12% endemics, 289 fishes with 41% endemics and 135 amphibians with 75% endemics (http://wgbis.ces.iisc.ernet.in/biodiversity/pubs/ ces_tr/TR122/index.htm).

Western Ghats has numerous watersheds that feed perennial rivers of peninsular India. It encompasses series of West and East flowing rivers that originates from the Western Ghats, supporting as source of sustenance for existing life forms in the environment. One such source of perennial waters is  Yettina holé originating at an altitude of 950 m in Sakaleshpura taluk of Hassan district, and tributary of river Gundia, which joins Kumaradhara and finally drains to Netravathi River. Yettinaholé and its immediate neighboring catchments falls under the Ecological Sensitive Zone 1 (ESZ 1) [as per the  HLWG report (Chairman: Kasturirangan)] with severe restrictions to any developmental activities. As per the Karnataka Elephant Task Force (KETF), the catchment and its surroundings are one of the vulnerable regions for human animal conflict (Elephant Human conflict) and any developmental activities would directly have impact on elephant conservation, leading to increasing human animal conflicts. This necessitates conservation of the region and restrictions on  any developmental and infrastructural projects.

Infrastructure development proposals have been proposed to divert the water sources such as flood waters during the monsoon and use the same to supply water to the regions having deficit in water reserves for agriculture and other activities. The project proponents ignores the implications on the surrounding environment such as loss of biodiversity both in fauna and flora, loss of endemics, riparian’s, variation in the upstream and downstream hydrologic regimes due to the variations in the natural flows etc. Many studies have clearly established implication of construction of dams or weirs across the streams or rivers have affected the downstream users with less productive estuaries, conversation of the wetlands to plantations due to scarcity of water resource during post monsoons and etc. Literatures and reports have also highlighted that with non-availability or due to the controlled water flow, many of the flood plains, river banks and beds are being converted to agriculture fields for better yield; large number of farmers tend to extract water from the ground water through deep bore wells in deprivation of higher yield and thus fluctuating or depleting the ground water table during non-monsoons. This report is aimed to express the effects of  water diversion scheme in a very sensitive and pristine environment by assessing the environmental water availability through water balance studies considering various aspects of water demand.