The need to take environmental considerations, to launch successful eco-friendly developmental project is increasingly getting recognised throughout the world. Environmental Impact Assessment (EIA) of the proposed project provides the much needed knowledge of the environmental consequences of such projects. It also provides adequate knowledge of the future impacts of the project and thus offers solutions to minimize the probable impacts of the project action.

Losses in biodiversity have become widely recognized as serious consequences of various human activities. Moreover, there are many direct as well as indirect benefits of biodiversity conservation. Therefore, conservation of biodiversity in economic, moral, aesthetic and intrinsic terms is important. It is impractical to conserve all aspects of biodiversity to the same extent all the time and in all the places. It is therefore necessary to have an EIA conducted to evaluate and suggest, where conservation efforts can best be applied for the optimum effect.

2.1 MACRO LEVEL ASSESSMENT
Project details (including the project design, route selection and relevant maps) were obtained from M/s IPCL, Baroda. The route maps were used extensively during the field reconnaissance and intensive studies. In addition, relevant toposheets (1:50,000) were also obtained from Survey of India for planning the detailed studies in the field. All possible sources of secondary information from published sources and other records were utilised for more detailed information of the project area and the study components.

For macro level assessment, the Survey of India toposheets and the maps of the proposed pipeline route were used to identify the protected areas (National Parks & Wildlife Sanctuaries) and ecologically sensitive ecosystem/wildlife habitats enroute the proposed pipeline.

2.2 FIELD BASED STUDIES
All field based studies were planned with an assumption that the disturbances associated with the construction activities would be uniform all along the proposed route of the pipeline. The impacts on the areas of ecological interest needs to be evaluated more carefully to meet the present scope of this study.

2.2.1 Reconnaissance Survey
The field work for DGB pipeline project was undertaken during August 1994. A WII research team undertook the survey of the entire route of the proposed pipeline. A representative from EIL, Dahej (GPC) provided all the necessary information during the entire course of field work. All along the pipeline route, survey points laid by IPCL were located. A total of 35 survey points were located during the rapid assessment survey. For these points details including the numbers indicating chainage and turning points, land-use category and wildlife values were recorded. The wildlife habitats identified during the reconnaissance survey were revisited for intensive studies to evaluate probable impacts upon them.

2.2.2 Intensive Survey
Based on the macro level assessment and reconnaissance only three ecologically sensitive areas were identified. All the three areas were wetland ecosystems. These wetland ecosystems are i) Dhadhar river ii) Aladar creek and iii) Chanchwel creeks. Intensive studies were conducted in these three areas. Data on physical characteristics (width/depth) and seasonality of these wetlands were recorded. Wildlife values for these wetlands were evaluated based on the direct sightings of wildlife species and any other information obtained from secondary sources.

2.3 EVALUATION OF WILDLIFE VALUES
Presence/absence of wildlife species for the three areas were considered for evaluation of the wildlife values of the wetlands. Representation of faunal groups (Fishes/Amphibians/Reptiles/Birds) in each of these three areas was determined.