All forms of large scale electricity generation have environmental impacts and the role of hydropower needs to be objectively assessed in that context. To understand the environmental effects of hydropower in a global energy system, the following points need to be considered
Loss of Habitat and Biodiversity
- Responsible hydropower developments have an interest in ensuring that the large financial investment in the project is not jeopardised by catastrophic erosion and siltation and loss of storage within the reservoir. All future projects in Lao PDR require a catchment management program that will primarily focus on reforestation and catchment protection. These programs will not only ensure the stability of the catchment but will also re-establish fauna habitats. The programs will be best integrated within a Protected Area Management System funded mainly from income generated from the hydropower development
Disruption of Human Settlement
- In Lao PDR the sparse populations within most of the mountain valleys reduces the social cost of resettlement programs and also provides alternative areas for resettlement. Culturally, many communities residence within an area is traditionally temporary. The need to move to new locations is determined by resource availability - as resources are depleted within their area, so the community will move the village to a new location. This historical patterns reduces many of the social concerns associated with resettlement requirements.
- To assist community development and improve the social equity of the project GOL now requires a developer to meet multilateral agency standards and to provide a continuing portion of the project's income to any dislocated community for social development programs. World Bank standards on resettlement specify that every household should be better off after being resettled
- Benefits accruing from resettlement may include rural electrification, improved roads, hospitals and education facilities. Cheap electricity, perhaps in conjunction with multi-purpose design of the hydropower project, can be used to replace rainfed paddy land with irrigated paddy and cash crops. Headponds and reservoirs can be stocked with fish and management systems provided including restrictions on opportunistic in-migration to ensure that these resources are not overfished. The community's health and nutrition status will also improve as part of a gradual improvement in socio-economic conditions
Reduction of Atmospheric Emissions
- Hydropower uses falling water as its energy source and is a totally renewable source of energy. It has an energy conversion efficiency of close to 100%. By contrast the main alternative to hydropower is thermal generation which has lower efficiencies (33 - 40%) and is associated with degradation of the atmosphere, global warming and acid rain formation. Acid rain from thermal generation is a growing regional problem in South East Asia.
- Global warming from the atmospheric build-up of C02 released from high carbon fossil fuels is an increasing concern. With energy growth within the region projected to double every seven years, the consequences of relying exclusively on thermal power for energy generation will have major regional and significant global consequences
Magnitude of Impacts
- The environmental impacts of hydropower projects are predominately local. Many of the construction impacts are short term and will heal with time. The severity of long term impacts is dependent on the site and the design. Large hydropower projects generally attract more vocal criticism but some larger hydropower projects have lower overall environmental impacts per unit of energy produced than smaller projects and may represent a more optimal development from both economic and environmental perspectives
|
