The consideration of alternatives to a proposal is a requirement of many EIA systems. It lies at the heart of the EIA process and methodology. During the scoping process, alternatives to a proposal can be generated or refined, either directly or by reference to the key issues identified. A comparison of alternatives will help to determine the best method of achieving project objectives while minimising environmental impacts or, more creatively, indicate the most environmentally friendly or best practicable environmental option.
Often, however, the consideration of alternatives is a superficial rather than a meaningful exercise. This is particularly true of private sector proposals, where the requirement to analyse alternatives is less than for comparable public sector proposals. It is also true of all proposals that are submitted to EIA when planning is nearly complete and the components and location are fixed already. This practice is becoming less and less acceptable as EIA matures and as sustainability issues and cumulative effects take on greater importance.
The consideration of alternatives is likely to be most useful when the EIA is undertaken early in the project cycle. Depending on timing, the type and range of alternatives open to consideration might include:
- demand alternatives (e.g. using energy more efficiently rather than building more generating capacity);
- input or supply alternatives (e.g. where a mix of energy sources permits);
- activity alternatives (e.g. providing public transport rather than increasing road capacity);
- location alternatives, either for the entire proposal or for components (e.g. the location of a dam and/or irrigation channels);
- process alternatives (e.g. use of waste-minimising or energy-efficient technology); and
- scheduling alternatives (e.g. for airport and transport operations, reservoir drawdown).
The World Bank recommends a tiered approach to the analysis of alternatives, which broadly corresponds to the headings above. It is designed to bring environmental considerations into all stages of development planning. This approach, ideally, begins with strategic environmental assessment (SEA) to analyse broad alternatives within a sector (such as power) or for a region. When this framework is not in place, as is frequently the case, the key alternatives are examined as part of a project-specific EIA. An application of the tiered approach in this context is illustrated further in case study of the Nam Theun II Hydroelectric Dam in the EIA Wiki.
In many cases, a fully tiered approach may not be possible. Certain alternatives will have been foreclosed by earlier stages of decision-making. However, some alternatives may remain open and a preliminary scan can help to identify them. Normally, a retroactive analysis of alternatives is not considered to be good practice unless circumstances warrant; for example a proposal may be well advanced but have a potentially significant impact on the environment or involve the relocation of large numbers of people.
The development of feasible alternatives, to meet the overall objectives of the proposal calls for certain types of information and knowledge. During this process, for example, reference may be made to: available technology, policy objectives, social attitudes, environmental and site constraints and project economics, as demonstrated in the case study of the Ghazi-Barotha Hydropower Project in the EIA Wiki. It is important to make sure that the alternatives chosen for comparison with a proposal can be implemented cost-effectively. Stakeholder input can be helpful in the generation and analysis of viable alternatives, but this needs to be used selectively. For example, the affected communities would have a minimal role in the review of demand and supplyside alternatives to the Nam Theun II project, but a primary one in assessing the environmental and social suitability of location alternatives.
The range of alternatives selected for analysis routinely includes the â€˜no actionâ€™ alternative. The relative impact of each alternative is compared against the baseline environment (with versus without project) to select a preferred alternative, including taking no action (which may not correspond exactly to maintaining baseline conditions because changes result from other actions).
In many EIA studies, the preferred alternative will be the most closely examined, and may be the only alternative to be considered in detail. However, it is not uncommon for several alternatives to be investigated at the same level of detail during the impact analysis and evaluation phases, prior to selecting from among them.