Reviewers of impact prediction methods argue that the foremost step of impact appraisal must consider and identify project actions that are likely to bring significant changes in project environment.

The following are some of the impacts that any pipeline project would have on biological values of natural habitats en route.

• clear felling of terrestrial habitats within the RoW.
   
• diversion of water flow from the aquatic bodies en route the proposed pipeline.
   
• influx of labour into the wildlife habitats.
   
• construction of a trench (which would sometime involves blasting in rocky terrain) to lay the pipeline.
   
• transportation of material and equipment to the project site.
   
• construction of storage sheds for material and equipment.
   
• drilling, welding and hydrotesting of pipeline.

The Bombay-Manmad Pipeline Project is also likely to impact upon some biological values of the habitats en route the pipeline. The magnitude of the impacts would however vary.

The severity of these impacts have been determined based on the habitat types, their floral and faunal values, spatial and temporal attributes of impacts and the availability of mitigatory measures.

4.1 IMPACTS ON TERRESTRIAL HABITATS
The proposed pipeline would pass through two major terrestrial habitats - forest and grassland. The prediction of impacts of the project on terrestrial habitats is based on the following considerations -

• length of the pipeline route proposed through the wildlife habitat
   
• width of RoW
   
• legal status of the habitat
   
• existing status of floral and faunal values
   
• existing status of habitat quality
   
• existing levels and sources of disturbances associated with industrial expansion and resource utilisation within the wildlife habitat

The impacts of the proposed project are discussed below separately for each forested habitat.

4.1.1 Jerandi Forest
The length of the proposed route through this forest is 2.3 km. Although, this route along the cart road is the best available option to minimise impacts on Jerandi Forest yet, the impacts of the proposed project would have to be evaluated to ensure environmental safeguard. The impacts of the project on the forest habitat are visualised at two different phases of the project.

i) Construction Phase

ii) Post construction Phase

i) Construction Phase Impacts

The major impacts of the proposed project are expected to occur during this phase of the project. The following are the major activities of this phase that are likely to have significant impacts.

• clearing of the forest within the RoW would involve removal of vegetation (trees, shrubs, herbs and grass cover) from the existing sub habitats
   
• within Jerandi Forest. This would not only lead to reduction in quantitative parameter of the habitat i.e., food, cover and shelter for the existing faunal species but is also likely to accelerate the process of soil erosion.
  the construction phase related activities particularly those involving removal of vegetation would be a direct threat to fawning grounds of ungulates. These activities are also likely to interfere with the breeding cycle of most wildlife species.
   
• the blasting activity for trenching for pipeline is likely to increase tree species mortality and thereby hasten the process of soil erosion. However, since the project authorities (BPCL) have confirmed that no blasting would be involved in the construction activities within the Jerandi Forest, no major impacts arising from blasting are being anticipated on wildlife values of Jerandi Forest habitat.
   
• although no new network of road is being proposed during project implementation phase, transportation of material and equipments would bring in lot of vehicular traffic, that would disrupt movements of wild animals.
   
• it is being assumed that the storage sheds for the material and equipment would not be constructed in the forested tracts of this region, and therefore no impacts of construction related activities are visualised on wildlife species of this forest.
   
• clearing of the forest within the RoW would lead to the formation of several small patches of fragmented forests within Jerandi Forest. This fragmentation of habitat would temporarily displace the residential bird species (like Bulbul, Flycatchers, Drongo, etc.), which are distinctly forest dwelling birds usually preferring undisturbed and unfragmented habitats within the forest. Past experiences also suggest similar impact of forest fragmentation due to strip mining and linear expansion (Hooper, 1967; Conner et. al, 1975 and Allaire, 1978). Since the different vegetation strata in the forest provide diverse foraging guilds and breeding and nesting grounds for avifaunal species, clearing of vegetation within the RoW, both at the ground level and at the emerging canopy level is likely to impact upon the breeding ecology of some of the avifaunal species of this forest habitat.
   
• the project is likely to involve hiring of large number of skilled and unskilled labour. The influx of labour is likely to increase pressure on forests for the provisions of timber (for camping), fuel wood (for cooking) and water for drinking and other domestic uses. This would be an additional pressure on the forest that are already under tremendous stress from biotic pressures.

ii) Post Construction Phase Impacts

The following activities can be visualised in the post construction phase of this project that can be considered for evaluating the impacts.

• clear felling within the RoW is providing additional channels to local people to seek access into the undisturbed and contiguous forest interiors for extraction of forest resources and hunting for wildlife (Plate 4.2).
   
• patrolling and inspection of pipeline which would apparently be a regular activity during the post construction phase is not expected to have any likely impacts upon wildlife values.
   
• leakage of products thorough pipeline would normally cause significant hazards. However, the statistics of incidence of leakage through pipeline do not lead to the probability of hazards associated with leakage.

Jerandi Forests are one of the few forest habitats en route the pipeline that support diverse fauna ranging from small burrowing animals (Indian hare and Indian porcupine) to large mammals (barking deer, four horned antelope, leopard, hyaena, etc.). They are crucial wildlife habitats as these are largely unfragmented and contiguous with adjacent forest stretches and therefore have the potential to support faunal species that require vast contiguous areas for their home ranges. It is likely that the proposed project would disrupt the movements of animals like leopard, hyaena, wild pig, barking deer and four horned antelope and would also reduce the breeding and foraging grounds for avifaunal species.

It is for this reason that the concern arising of the project actions on wildlife values of Jerandi Forest are well visualised and the significance of the impacts are well understood to formulate mitigatory measures.

4.1.2 Phugala Forest
The length of the proposed pipeline route through Phugala Forest is 2.5 km. The impacts of project on this forest is also visualised for both construction and post construction phase.

i) Construction Phase Impacts
The construction phase is likely to have an overall low impact on the wildlife values of Phugala Forest. The following are some of the factors that have been considered to determine the impacts on Phugala Forest.

• most of the trees within the RoW are already affected by severe lopping and cutting pressure (Plate 4.1). These biotic disturbances would only hasten the degradation trends already prevalent in the area by reducing the existing forest cover values and thereby also the potential habitat quality.
   
• though the blasting activity for the construction of trench would physically impact only a small stretch of pipeline route passing through rocky terrain, the impacts of other activities like drilling, welding, hydrotesting, etc. is also likely to aggravate the degradation process of this forest area.
   
• since no direct and indirect evidences of existing faunal species are available from this forest stretch, no significant changes are visualised in the faunal values of this habitat that can be attributed to project activities and that can be considered to induce impacts.

ii) Post Construction Phase Impacts

The impacts of post construction phase during the study of this project are relatively low. The reduced faunal diversity and insignificant faunal numbers are a reflection of low habitat potential of these forests. No further changes in the above values are predicted as an after effect of pipeline laying operation.

4.1.3 Grassland
The proposed pipeline would cover 0.9 km length of grassland habitat located in Sinnar. The impacts of the proposed project are expected to be fairly low on Sinnar Grassland habitats. The small size of grassland habitat, the low faunal/floral values and commercial harvest of grass from this reserved forest are the three most important factors that have already reduced the biological potential and the conservation significance of this grassland habitat. The project related actions do not seem to be imposing any major impact that would further threaten the wildlife values of this area.

4.2 IMPACTS ON WETLAND HABITATS
The prediction of the impacts of proposed pipeline route on the wetland habitats was based on the following ecological and technological considerations-

• seasonality of the wetland (perennial or seasonal)
   
• total length of pipeline route through wetland
   
• choice of technology to be adopted for laying the pipeline
   
• floral and faunal values of the wetland
   
• existing level of biotic pressures (fishing, harnessing of water and contamination by industrial effluents)

The impacts of pipeline on creek, lake and river corridor are dealt under different heads as under:

4.2.1 Ulhas Creek
The length of the proposed pipeline route through Ulhas Creek is approximately 0.4 km. No significant impacts of the project are visualised on this creek due to the following habitat characteristics of this wetlands.

• the creek does not harbour any wildlife species of conservation significance.
   
• there are no breeding records of any aquatic wildlife species in the stretch of the creek through which the proposed pipeline route is aligned.
   
• the creek water is highly polluted due to inflow of toxic industrial effluents.
   
• the overall wildlife value of the creek is low due to low floral and faunal diversity.

4.2.2 Lake Beale
The proposed pipeline route is aligned along the periphery of the Lake Beale for a length of approximately 2 km. As is evident from the baseline information presented in the preceding section, except few residential birds, the lake doesn't support any significant migratory waterfowl population.

The lake also supports few species of fishes as is evident from the small size of fish catch and the few species that constitute the total fish catch from the lake. It may however, be considered here that the size of the fishes in the catch is fairly small. Even without the initiation of project activities there is a potential threat to the lake population of fish from the fishermen (Plate 4.2) and other activities which affect the wetland habitat quality. The proposed pipeline would therefore have no direct impact in the further depletion of fish fauna of Lake Beale. The chelonian is represented by only one turtle species - the Indian Flap Shell Turtle, which is fairly common.

The local people are already using this lake as a source of water for domestic and irrigation purpose. It is also likely that the water would be drawn from the lake for various construction activities and hydrotesting of pipeline. This would be an additional pressure on the lake, leading to reduction in the water level of the lake and thus affecting the existing diversity of flora and migratory water fowl.

Since the proposed pipeline route is aligned very close to the lake, there would be risks of accidental leakage leading to water pollution in absence of sophisticated monitoring equipments.

4.2.3 River Corridor
The length of the proposed pipeline route through Godavari River Corridor is approximately 0.07 km. The habitat quality of river is already impacted by the fluctuating water levels due to the construction of dam upstream. The stretch of the river within the proposed pipeline route therefore, does not support wildlife species of conservation significance. There are also no records of breeding sites of aquatic wildlife species in this stretch to further strengthen the views on the wilderness values of this wetland. The river stretch en route the pipeline dries up during summer months and this is not conducive to the formation of riparian habitats that would support bank flora.

The only likely impact that has been visualised is that of accidental leakage of petroleum products into the water. This too seems to be a remote possibility as the project authorities have ensured the use of highly sophisticated and computerised leak detecting and monitoring systems.