Also, the submergence may lead to loss of homes, means of subsistence like agricultural, horticultural and even forest lands, where tribal have access to minor produces as well as for humming, and naturally will have a traumatic effect on the affected population. Under such circumstances, it will be proper to take timely steps for planning rehabilitation and resettlement of Project Affected Persons (PAPs) to avoid any further disastrous incidents.
Due to varied geomorphic character, complex tectonics, structure, and soft sediment lithostratigraphy, and change in drawdown, the impounded water are bound to cause unstable slope condition, especially in reservoir rim, particularly those in the limit of drawdown. Thus, in the event of sudden drawdown, a major slide could develop. Simultaneously, reservoir water would act as the load drive, as is commonly found in the Himalayan Region, which may have a positive stabilizing influence too. It is therefore recommended that about 100 m above the reservoir rim is thoroughly investigated for site-specific knowledge on failure mechanism and adequate protection measures, as explained, be planned at the pre-construction stage with the tentative provision of shot creating, rock anchoring, carving out of slopes, etc.
Landslide activity would generate rock boulders, silts, and mud, but its effect is again dependent on the distance of occurrence from the project components. If the slide occurs much above the FRL direct impact would be less. However, some slides just at the periphery of the rim would add to the silt load/bed load.
This impact on the project could be managed by arresting the potential slide zones through suitable engineering treatment measures, afforestation, 4etc. However, the project shall have a separate provision for engineering geological studies to provide necessary treatment measures.
Monitoring Gas Emission
During construction/excavation of underground openings in the project site, emission of explosive gas may be encountered as the lithological sequence to be encountered is of tertiary age. Therefore, its adverse effect of the damaging environment during construction period could be mitigated through early monitoring of the quantity and quality &. concentration of the gas. For this gas detector and protective measures, as per underground construction/mining rule is to be kept and executed strictly.