Saltwater ingress also causes salinisation of drinking water as saltwater seeps into the underground aquifers. Bharuch currently lies on the eastern fringe of an extensive zone with saline groundwater. Large areas on both banks are likely to be affected by an extensive ingress of salt into groundwater after dam construction ( CD Patel 1993). Those farmers using groundwater for irrigation are also likely to be seriously affected. A similar fate has already struck several villages on the banks of the Mahi river (north of the Narmada), where groundwater has not only turned saline, but the river water too is undrinkable for half the month due to high salinity and pollution ( CD Patel 1993).

Reduced water flow can affect the shape of the land itself. In the Gulf of Khambat, there is a net transport of sediments towards the land due to the high tidal range ( CD Patel 1993). In the Mahi river mouth, severe erosion of the northern bank has been attributed to the Mahi and Panam dams, as reduced flow has changed the pattern of deposition and the erosion of tidal forces. Similar bank erosion may occur in the Narmada, and the river mouth may be blocked due to reduced flow. The river may be forced to carve out new channels. This would also affect the functioning of Bharuch port.

The impacts of SSP on the estuarine ecosystem are still under study ( NCA 1993) hence workplans are not yet finalised. It is simply stated that action plans will be worked out to counter the impacts. As such, we cannot comment on the adequacy or otherwise of the ameliorative measures. It is clear that water will have to be released from the dam throughout the year to prevent salt ingress, which could reduce the irrigated area of the SSP. Whether this will actually happen only time can tell.

The command area of SSP is probably the most neglected in terms of environmental impact studies. The 1983 M.S. University report completely ignored it, and studies on various impacts were mostly started only after obtaining conditional environmental clearance. The latest relevant NCA document, of June 1993, states that "studies are ongoing to complete the work necessary to compile an environmental assessment of the development of the Command Area ... The results of these studies, most of which should, be available within one year, and which should all be available by the end of I994, will be used to devise an environmental management plan for the Command Area." ( NCA 1993).