Mitigation and compensation hierarchy Mitigation and compensation should be

considered in a hierarchy, consisting of avoidance, minimisation, rectification,

compensation and enhancement measures. This is shown in Figure 10.2.

Priority should be given to avoiding impacts at source, e.g. through the re-design of a project

Figure 10.2: Hierarchy of mitigation measures

Source: Rajvanshi (2008), modified from UNEP (2002)

Highest

Priority

Lowest

Avoid the potential impact

Decrease the spatial/temporal scale of the impact during design, construction, etc.

Apply rehabilitation techniques after the impact has occurred

Offset the residual impact and compensate, as appropriate

Avoid Minimize

Rectify Compensate

proposal or by changing the timing and location of activities. In this context, the precautionary principle should be applied, in particular in situations where the level of uncertainty of a project is high. If avoiding significant negative impacts is not possible, they should be reduced. If significant negative environmental impacts still remain, compensation may be necessary. However, this should only be applied if all other measures from Figure 10.2 have been

considered. Figure 10.3 explains the different mitigation measures introduced in Figure 10.2 further, referring to ‘approaches for mitigation of impacts’ (following Rajvanshi, 2008).

Subsequently, measures to avoid and minimize impacts are discussed further before remedial action is considered.

10.3.2 Avoiding environmental impacts

There are various possibilities to avoid environmental impacts. These include the

consideration of alternatives, sensitive design, environmentally sustainable technology, development restrictions in sensitive areas, avoidance of certain key areas, adopting the ‘precautionary approach’, and finally, refraining from certain action altogether.

Identification of alternatives:

The identification of least impacting alternatives is at the heart of any EIA. A range of possible impacts were introduced above. A specific alternative can lead to avoiding impacts on sensitive environments, such as human settlements, biodiversity rich areas, habitats of endangered species, archaeological and cultural sites of proposed projects.

Sensitive design:

Adopting environmentally sensitive design of development projects can help to avoid many

Figure 10.3: Approaches for mitigation of impacts

Source: Rajvanshi (2008, p.168)

Mitigation by avoidance

Measures considering siting, design, process, technology, route alternatives and ‘no go’ options to avoid impacts.

Represents cheapest and most effective form of impact mitigation. This approach offers the greatest benefit of avoiding impacts early in the planning cycle.

Compensation

Represents measures to achieve no net loss.

Represents on-site or off site measures considered early in the planning process and also alongside the development to offset residual impacts.

This approach opens a window of opportunity for negotiations between developers and decision-makers.

Enhancement

Represents measures to achieve net positive gain.

Applied in parallel with other compensation measures to encourage opportunities to limit the scope and scale of impacts and on improving environmental features. This approach may result in a win- win situation and improve prospects for project acceptability.

Mitigation by reduction

Measures attempting to reduce impact or to limit the exposure of receptors to impacts.

Applicable only in the progressive phase of the development project. This approach aims at limiting the severity of impacts and not avoiding them altogether.

Mitigation by remedy

Measures undertaken to restore the environment to its previous condition or to a new equilibrium.

Applicable only towards the end phase of project implementation. This ‘end of pipe’ restorative approach helps improve adverse conditions created by the proposed development.

impacts. ‘Nature engineering’ concepts have been discussed by a range of authors (Canters et

al., 1995; Spellerberg, 1998; Forman and

Sperling, 2003) and are being implemented in practice in many countries. This can include e.g. road underpasses and bridges for animals or fish ladders on dams. Artificial nests also fall into this category.

Environmentally sustainable construction and technology:

Environmentally sustainable construction and technology for controlling impacts and making good environmental choices are also important. Environmentally sustainable technology can be applied during construction, post construction and in progressive phases of a project. Development restrictions in sensitive areas: In many countries, there are restrictions on locating projects in specific areas. In the UK, the ‘Green Belt’ has protected open space around major conurbations, keeping development and sprawl in around metropolitan areas to a

minimum. The same applies to the Dutch ‘Green Heart’, an area with development restrictions between Amsterdam, the Hague, Rotterdam and

Utrecht. In Germany, the landscape planning system identifies, in an area wide manner, sites suitable for defined developments and sites with development restrictions (Hanusch and Fischer, 2008). Development controls are being

increasingly enforced in other countries.

Avoiding development in certain areas altogether: An effective way for avoiding negative

environmental impacts is to avoid development in certain areas altogether. This may include, for example, estuaries, salt marshes, wetlands, shore lines and specific sensitive habitats such as breeding grounds, rearing areas, over wintering sites and migration routes. There is an emerging consensus on ‘no development’ zones (Box 10.2), based on guidelines of various international bodies (WWF, 2002; EBI, 2004; IFC, 2004). Some institutions have adopted a no development zones approach. These include e.g. the US Overseas Private Investment Corporation, a bilateral finance agency, which categorically prohibits projects in or impacting IUCN I-IV protected areas, World Heritage Sites, and projects that involve conversion or degradation of critical forest areas or related critical natural habitats. Also, the Bank of America will not

Box 10.2: Criteria for recognising high conservation value sites as ‘No-Development’ zones l Protected areas, core areas of biosphere reserves and Ramsar sites not included under IUCN category I-IV

of Protected Areas.

l Proposed protected areas in priority conservation areas.

l Sites that maintain conditions vital for the viability of protected areas that support 'jewels'. l Centres of plant diversity.

l Areas officially proposed for protection based on local and national priorities.

l Area of known high conservation value, these may include sites of degree of endemism, rarity, vulnerability, representativeness and ecological integrity.

l Areas where there is a lack of knowledge of biodiversity.

l Areas where operations will reduce populations of any recognised critically endangered or endangered species, or significantly reduce the ecological services provided by an ecosystem.

l Areas recognised as protected by traditional local communities. l Critical fish breeding grounds.

l Areas where there is a serious risk of soil, watershed, pollution, and knock-on effects such as land invasion.

finance projects that include resource extraction from high conservation value forests, primary tropical moist forests, and primary forests in temperate or boreal forest regions (IUCN, 2005). Timing of activities:

Many countries have regulations in place with regards to scheduling certain activities as to take place in defined times only. This is done in order to avoid overlaps with e.g. flowering and seeding, nesting or breeding seasons.

Adopting the ‘precautionary approach’: The precautionary approach means preventive decisions are to be made in the face of

uncertainty in order to protect the environment. Probably the best known document putting forward the Precautionary Principle internationally is the Rio Declaration from the 1992 United Nations Conference on Environment and

Development (Agenda 21). It promotes action to avert risks of serious or irreversible harm to the environment (Cooney and Dickson, 2006). The Precautionary Principle has been integrated into numerous international conventions and

agreements. One of the first countries to have included the precautionary principle into environmental legislation is Germany, where the idea can be traced back to the first draft of the clean air legislation in 1970 (Wurzel, 2006). Refraining from certain developments:

Refraining from certain developments altogether means avoiding particular impact-causing actions. An important question to ask is thus whether a particular development is needed at all, even though in practice this may often be

difficult.

10.3.3 Minimising environmental impacts