IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 03 Special Issue: 06 | May-2014 | RRDCE - 2014, Available @ http://www.ijret.org 45 WATER AND SOIL QUALITY ASPECTS OF NELLIGUDDE RESERVOIR CATCHMENT AND COMMAND AREAS; MAGADI TALUK, RAMANAGAR DISTRICT: A CRITICAL STUDY K.V. Lokesh 1 , H. Chandrashekar 2 , Joythi Roopa 3 , G.Ranganna 4 1 Professor, Dept. of Civil Engg, Dr. Ambedkar Institute of Technology, Bangalore 560056, Karnataka, India 2 Selection Grade Lecturer, Department of Civil Engineering, MEI Polytechnic, Rajajinagar, Bangalore- 560010,.Karnataka, India and Research Scholar, Dr.Ambedkar Institute of Technology, Bangalore-560056 3 Research Scholar, Dr.Ambedkar Institute of Technology, Bangalore-560056, Karnataka, India 4 Visiting Professor, CAS in Fluid Mechanics, Bangalore University, Bangalore, Karnataka, India. Abstract Tanks and lakes occupy a prominent place in the history of irrigation in South India. A tank was considered to be a useful life saving mechanism in the perennial water scarce areas, which are categorized as arid and semi-arid regions. Tanks are the main source of water supply in those areas for ages. Tanks occupy an important place in the economy of a village and are almost considered to be the back bone of rural economy. Due to urbanisation and improper management, these irrigation tanks are in the state of deterioration. Hence, management of tanks and lakes is of prime importance, and need of the hour. The paper discusses the present status of Nelligudde tank in Magadi Taluk of Ramanagara District(Karnataka). The physico-chemical analysis and results of bacteriological analysis of water samples drawn from the tank catchments and command areas are presented. The results reveal that water is highly contaminated and unfit for drinking and irrigation purposes. The micro and macro nutrient analyses of soil samples collected in the catchments, tank beds and command areas also reveal that the soil is contaminated. The tank bunds are partially eroded. The waste weirs and sluices are to be restored and modernised. Rapid urbanisation and industrialisation in the Lake Catchment and intensive irrigation have resulted in the deterioration of quality of lake water and soil in the catchment and command areas. Modernisation of tank irrigation system should be of prime importance. Illegal construction projects are coming up in the flood plain areas destroying raja kaluves. The paper also discusses some aspects of management of these lakes. Keywords: Lake Catchment, Urbanisation, Irrigation Techniques, Lake Management, USSL diagram. --------------------------------------------------------------------***---------------------------------------------------------------------- 1. INTRODUCTION The awareness that water is no longer a free and plentiful natural resource but is a precious economic commodity and imperiled social asset is yet to sink in. Experts and agencies both inside the country and outside have many times drawn attention to the depletion of water (particularly so with groundwater), shrinking of water bodies and the prospect of water in the coming years. The alarm sounded by the World Bank over the sinking groundwater table in India is not new. Therefore over-exploitation, misuse and lack of conservation and augmentation efforts are normal in the country. The scenario is bleak across the world, provoking comments that countries may in future resort to war over water. But the situation is especially critical in India (particularly in Karnataka) with an increasing population exerting greater pressure on the resource for agricultural, drinking water and industrial purposes. The over-use of water could lead to a reduction of agricultural output by as much as 25 per cent and lead to serious drinking water shortages. Industry will also be badly affected by the shortage. Better irrigation techniques, distribution of water through leak proof canals and educating farmers on the optimum use of water will help to stop the depletion of water. Economic use of water for irrigation can go a long way in maintaining the present availability. Rain water harvesting and preservation of lakes and other water bodies have been much talked about but action taken is unsatisfactory. Hence, techno ecological studies have been taken up on the status and management of Nelligudde tank located in Magadi Taluk, Ramanagaram district. Physico- chemical and bacteriological analysis of water samples in the lake catchment, in the lake and its command area were carried out. The soil samples in the catchment, lake and command area were analyzed for the presence of macro and micronutrients. 2. STUDY AREA The study area comprises, Nelligudde tank,its catchment and command areas situated in Magadi Taluk, a part of Ramanagaram district. The Nellegudde tank catchment and its command with a total extent of 65 Sq. Km is located adjacent