http://JUDIS.NIC.IN SUPREME COURT OF INDIA So far as the safety aspects of the dam are concerned, reliance is placed on the technical opinion of the exoerts, which says that a rock fill dam does not require three-dimensional studies to estimate its safety against earthquake. It is submitted that such computer based three-dimensional studies have been found to be only of theoretical value. Two-dimensional test already done fully ensures safety of the ’dam against an earthquake even up to 7 on Richter Scale. It is submitted that the two-dimensional studies of the dam is made on an assumption that the impact of earthquake of 7 or more Richter Scale would be uniform throughout the length and breadth of the dam. The experts have found such two-dimensional studies sufficient for the safety of the dam. Suggestion of only one of the experts for conducting a three-dimensional test only by way of an abundant caution has been found by the team of experts neither feasible nor desirable. Attempt has also been made by filing item-wise comments that various recommendations of Hanumantha Rao Committee were in-depth gone into by Inter-Departmental Committee and most of the recommendations except a few have been accepted and also substantially implemented in proportion to the construction work already undertaken. On behalf of the Corporation, a categorical statement has been made that until all the conditions for the clearance are not fulfilled, Tunnel Nos. 3 & 4 shall not be opened and the reservoir shall not be filled beyond its present water level. People presently living in the catchment area in Tehri town would not be evacuated till they are paid either cash compensation or land in lieu thereof, with shelter. The Corporation has also presented before us in the course of hearing Status Report of fulfillment of the various conditions at the project site up to 31.01.2003. The project for construction of large dams has been undertaken to provide electricity and irrigation facilities. From environmental and social prospective, large dams raise variety of issues. They entail massive incursions into natural eco-system and human settlements. When the project is undertaken, it is asserted that these incursions can be minimised by appropriate steps like Environmental Impact Assesssment and preventive/ ameliorative measures. It is with this porpose that the Environmental Act and rules require the project to take care of the adverse impact on environment and human population. Environmental clearance now is a legal requirement. A machanism has also been evolved for evalution of the environmental impact and its monitoring. Construction of large dams are accompanied by significant alterations in the up-stream and the downstream, physical and biological environment. For building reservoirs, large track of forest lands get submerged. Water logging and salinasation affect the canal irrigated land with varying degrees of severity. Several species of wild animals and plants become extinct. There is a likelihood of several diseases like Malaria spreading. On the positive side, the alleviation of water scarcity leads to improvement in the health standard of people and reduction in diseases caused by shortage of potable water. Barren lands become green. New habitats are created for water birds. In order to take care of the negative aspects of the large dams, the conditions for clearance generally require:1. Compensatory afforestation. 2. Treatment of catchment area to prevent prematured silt in other aspects. 3. Measures to prevent or minimise water logging and salinasation in the command area and around the reservoir. 4. Measures to prevent and minimise impact on health. Page 31 of 37