§3.2.2 Step 2: Assessing the implications of the plan or project in view of the site's conservation objectives, individually or in combination with other plans or projects

The appropriate assessment should include a comprehensive identification of all the potential effects of the plan or project likely to be significant on the site, taking into account cumulative and other effects likely to arise as a result of the combined action of the plan or project under assessment with other plans or projects. (The Article 6 Guide – section 4.6.2) The appropriate assessment should ensure that all structural and functional aspects that contribute to site integrity are considered in full, both in the definition of the baseline conditions and in the stages leading to identification of potential impacts, mitigation measures and any residual impacts after mitigation measures have been applied. Step 2 includes the following activities: — identifying the conservation objectives of the Natura 2000 sites affected by the plan or project; — identifying and assessing the impacts of the plan or project against the sites’ conservation objectives; — considering cumulative effects with other plans and projects. Identifying the conservation objectives of the Natura 2000 sites affected by the plan or project In the appropriate assessment, the effects of a plan or project must be assessed against the conservation objectives set for the protected habitats and species present in the Natura 2000 sites. Competent authorities must set conservation objectives for each site. The objectives must be established for all species and habitat types of Community interest under the Habitats Directive and bird species of the Annex I of the Birds Directive that are significantly present on a Natura 2000 site, as well as for regularly occurring migratory bird species. Site-level conservation objectives are a set of specified objectives to be met in a site in order to make sure that the site contributes in the best possible way to achieving favourable conservation status at the appropriate level (taking into account the natural range of the respective species or habitat types). Site-level conservation objectives should define the desired conservation condition of the species and habitat types on the site for maximising its contribution to achieving FCS [favourable conservation status] at the appropriate level. They are sometimes defined as a set of targets to be achieved over a certain period of time. These targets should be set in function of the conservation assessment of each species and habitat type on the site as recorded in the SDF [standard data form]. See further details in the Article 6 Guide – section 2.3.1, and the Commission Note on setting conservation objectives (available at: https://ec.europa.eu/environment/nature/natura2000/management/guidance_en.htm) The conservation objectives for a Natura 2000 site are usually set in the management plans or relevant management instruments, or in other documents published for the sites (e.g. designation acts published in official journals). They should also be publically available. Conservation objectives for each of the habitat types and species present in the site should be related to their ecological requirements and set with reference to the parameters used for determining its conservation condition on the site (e.g. their area, structure and functions or populations). They should specify targets to be achieved for each of these attributes/parameters. They should also include targets/limits for the ecological functions and processes on which the habitats and species depend (e.g. defining the required water quality and quantity for aquatic species). The conservation objectives must be: — specific – i.e. relate to a particular feature (species or habitat type) and define the condition(s) required to meet the conservation objective; — measurable and reportable – i.e. include quantitative targets (possibly supplemented by qualitative ones, such as a description of good condition of a habitat or a population structure), enabling monitoring to assess whether the conservation objectives are being met and for the purposes of Article 17 of the Habitats Directive; — realistic – i.e. given a reasonable timeframe and application of resources; — consistent in approach – i.e. the structure of conservation objectives should, as far as possible, be the same across all sites, and at sites supporting the same feature, use similar attributes and targets to describe favourable conditions; and — comprehensive – i.e. the attributes and targets should cover the properties of the feature necessary to describe its condition as either favourable or unfavourable. The objectives must also specify whether they aim to ‘restore’ or ‘maintain’ the conservation status of the given feature of the site (the level of ambition predetermining the necessary conservation measures). Adapted from ‘Commission Note on setting conservation objectives’ (available at: https://ec.europa.eu/environment/nature/natura2000/management/guidance_en.htm) The lack of site-specific conservation objectives or the establishment of conservation objectives, which are not in line with the standard described above, jeopardises compliance with the requirements of Article 6(3). Box 9 gives examples of site conservation objectives. Box 9 Examples of conservation objectives for habitat types and species in Natura 2000 sites Reefs (1170) — the permanent habitat area (xx ha) is stable or increasing, subject to natural processes; — the distribution of reefs is stable or increasing (map provided); — the following community types are conserved in a natural condition: exposed intertidal reef community complex (xx ha); exposed subtidal community complex (xx ha) (a description of each of the community types is provided). Shifting dunes along the shoreline with Ammophila arenaria (‘white dunes’) (2120) — the habitat area (xx ha) is stable or increasing and there is no decline in its distribution (map provided), subject to natural processes; — the natural circulation of sediment and organic matter is maintained, without any physical obstructions (e.g. physical barriers); — the presence of species-poor communities dominated by Ammophila arenaria is maintained; — negative indicator species (including non-native species, species indicative of changes in nutrient status and species not considered characteristic of the habitat) represent less than 5 % cover. Dry heaths (4030) — the current surface area (xx ha) and distribution of the habitat within the site is increased by x % (map provided); — the abundance of typical species is maintained (list provided); — a low cover of scattered native trees and scrub (< 10 % cover) is maintained; — at least 1 % but not more than 10 % cover of the area of the habitat consists of bare ground; — nitrogen deposition is maintained below critical load values defined for the site (e.g. 10-20 kgN/ha/yr). Molinia meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae) (6410) — the current surface area (xx ha) and distribution of the habitat within the site is increased by x % (map provided); — the vegetal composition is improved: at least xx positive indicator species present, including one ‘high quality’ species, negative indicator species cover collectively not more than 20 % cover, with cover by an individual species less than 10 %, and cover of non-native species not more than 1 %; — the vegetal structure is improved: cover of woody species and bracken (Pteridium aquilinum) is not more than 5 %, broadleaf herb component of vegetation is between 40 and 90 %. At least 30 % of sward is between 10 and 80 cm tall; — the physical structure is maintained: not more than 10 % bare soil. Active raised bogs (7110) — the area of the habitat in the site is extended (e.g. increase the current area by 10 % – from xx ha to yy ha) and its condition improved (e.g. by increasing the cover level of characteristic bog mosses –Sphagnum species to a minimum of x %); — appropriate water levels are restored throughout the site (mean water level to be near or above the surface of bog lawns for most of the year; seasonal fluctuations should not exceed 20 cm, and should only be 10 cm below the surface, except for very short periods of time); — soil pH and appropriate nutrient levels are maintained (relevant nutrients and their natural ranges are provided for the site); — cover of scattered native trees and shrubs is less than 10 %. Beech forests Luzulo-Fagetum (9110) — the current conservation status is maintained (fav); — the current surface area of the habitat in the site: xx ha is maintained; — characteristic tree species are maintained: at least 70 % of canopy level composed of Picea abies, Fagus sylvatica ssp. sylvatica, Abies alba in various proportions, with rare presence of Betula pendula, Sorbus aucuparia, with an 80–90 % cover and 22–30 m height for spruce and fir, 18–24 m for beech at 100 years age; — characteristic species for herb layer are maintained: Herb layer with at least three species/1 000 m2 of the following acidophilous species Calamagrostis arundinacea, Luzula luzuloides, Vaccinium myrtillus, Hieracium rotundatum, Athyrium filix-femina, Digitalis grandiflora, Dryopteris filix-mas, Festuca drymeia, Galium odoratum, Galium schultesii, Lamium galeobdolon, Luzula luzuloides, Oxalis acetosella, Poa nemoralis, Pteridium aquilinum, Veronica officinalis; — invasive and allochtonous tree species, including not-corresponding ecotypescover less than 20 %; retention trees: at least three trees/ha; deadwood volume: at least 20 m3/ha. Asperulo-Fagetum beech forest (9130) — the current surface area (xx ha) and distribution of the habitat within the site is increased by x % (map provided); — the habitat quality (in terms of ecological structure and function) is improved by ensuring that: at least 95 % of canopy forming trees are locally native species such as beech, ash and oak site, with at least 50 % being Fagus sylvatica; approximately 10 % of the canopy includes a dynamic shifting pattern of gaps encouraging natural regeneration of tree species of all ages; at least X mature trees/ha and at least X relevant ground flora species/ha (list of relevant species provided); — dead wood, standing and fallen, is increased where possible to provide a habitat for invertebrates, fungi and other woodland species (fallen trees and branches, dead branches on living trees or standing dead trees, all > 20 cm in diameter; minimum volume indicated). Otter (Lutra lutra) — the current population (xx individuals) is maintained; — the ecological quality of freshwater (river) habitat is improved (over xx km); — the number of couching sites and holts (number provided) is maintained and there is no significant decline in the fish biomass available (xx kg); — connectivity with other otter populations along the river is improved. Harbour porpoise (Phocoena phocoena) — the current population of the species in the site is maintained (xx individuals); — underwater noise to maximum is limited to xx dB; — species range within the site is maintained by ensuring there are not artificial barriers that could restrict site use; — the availability and density of prey within the site is maintained(e.g. including sand eel, whiting, herring and sprat); — by-catch of harbour porpoise in fishing gears in the site is prevented. Lesser Horseshoe Bat (Rhinolophus hipposideros) — the population is maintained, with a minimum number of xx bats for the summer roost; — the number and condition of summer and auxiliary roosts is maintained; — the extent of potential foraging habitat (xx ha) and linear features xx (km), is maintained with no significant decline or loss within 2,5 km of the roost (map provided); — there is no significant increase in artificial light intensity adjacent to the roost or along commuting routes within 2,5 km of the roost. In the absence of conservation objectives (28), the appropriate assessment should assume as a minimum that the objective is to ensure that the habitat types or habitats of species significantly present on the site do not deteriorate below the current level (at the time of the assessment) and that the species are not significantly disturbed, in line with the requirements of Article 6(2) (29). Although the focus of the assessment should be on the birds and the species and habitat types of Community interest significantly present on the site, it should not be forgotten that these target features also interact with other species, habitat types and with the natural environment in complex ways. In this regard, other species can also be relevant when looking at the potential effects on protected habitats if they constitute typical plant and animal species of the habitat type in question (30) or play a significant role in the food chain on which the Natura 2000 site’s target feature depend. This will be reflected in the site’s conservation objectives and the appropriate assessment should also look at the possible impacts of the plan or project on these other species where relevant. Landscape features that contribute to the ecological coherence of the network, including to its connectivity, should also be considered, where appropriate, in the assessment of the effects of plans and projects on Natura 2000 (see Table 4). Identifying and assessing the impacts of the plan or project in view of the site's conservation objectives All aspects of the plan or project that can, either individually or in combination with other plans or projects, affect the site’s conservation objectives must be identified in the light of the best scientific knowledge in the field. The appraisal of effects must be based on objective and, if possible, quantifiable criteria. Impacts should be predicted as precisely as possible, and the basis of these predictions should be made clear and recorded in the appropriate assessment report. See further details in the Article 6 Guide – section 4.6. The assessment must cover the impact of the entire plan or project in question, with all the activities it comprises, and during all phases (preparation, construction, operation and, where relevant, decommissioning or reconditioning). The assessment must identify and differentiate the various types of impact, including direct and indirect effects, temporary or permanent effects, short- and long-term effects and cumulative effects The assessment typically includes the analysis of the following possible impacts: — Direct loss : reduction of habitat coverage as a result of its physical destruction (e.g. due to its removal or to the deposition of construction materials or sediments); loss of breeding, foraging, resting areas for species. — Degradation : deterioration of habitat quality, leading to a reduced abundance of characteristic species or an altered community structure (species composition). This can be caused by changes in abiotic conditions (e.g. water levels or an increase in suspended sediments, pollutants or dust deposition); deterioration of breeding, foraging, resting areas for species. — Disturbance : a change in existing environmental conditions (e.g. increased noise or light pollution, a greater frequentation of people and vehicles). Disturbance may cause, inter alia, the displacement of species individuals, changes in species behaviour, or the risk of morbidity or mortality. — Fragmentation: leading to an alteration of distribution patches of relevant habitats and species, e.g. through the creation physical or ecological barriers in areas that are physically of functionally connected, or splitting them into smaller more isolated units. — Other indirect effects: indirect change to the quality of the environment (resulting for example from a change in availability of nutrients and light, or an increase in the vulnerability of the site to other new threats such as invasive alien species, human and animal penetration). These effects should be analysed in view of the site-specific conservation objectives, which implies that the analysis needs to be done not only in relation to the current condition of the habitats and species significantly present within the site but also in relation to their desired condition as defined by the conservation objectives (e.g. an increase in population size or habitat coverage by x %). An analysis of effects in view of the site-specific conservation objectives must also therefore be done on the basis of the specific attributes or parameters that determine the conservation condition of the protected features (e.g. range, habitat, structure and function, population size, future prospects). Each aspect of the plan or project should be examined in turn and its potential effects considered against the site’s conservation objectives. Then the effects on all the affected habitats and species should be looked at together, and in relation to each other, so that the interactions between them can also be taken into account. Different methods can be used to predict the potential impact of plan or projects. Box 10 lists some examples of methods that can be used to predict the impacts as well as the scale of the impact. Box 10 Examples of impact prediction methods Direct measurements, for example size of area of habitat lost or affected, can identify proportionate loss from species’ populations, habitats and communities. Flow charts, networks and systems diagrams identify chains of impact resulting from direct and indirect impacts, in line with how they are caused, illustrating interrelationships and process pathways. Quantitative predictive models provide mathematically derived predictions based on data and assumptions about the force and direction of impact. Models may extrapolate predictions that are consistent with past and present data (trend analysis, scenarios, analogies which transfer information from other relevant locations) and intuitive forecasting. Some commonly used models predict the dispersal of pollutants in air, soil erosion, sediment loading of streams, and oxygen sag in polluted rivers. Geographical information systems (GIS) can be used to produce models of spatial relationships, such as constraint overlays, or to map sensitive areas and locations of habitat loss. GIS are a combination of computerised cartography, storing map data, and a database management system, storing attributes such as land use or slope. GIS enable the variables stored to be displayed, combined, and analysed at speed. Information from previous similar projects may be useful, especially if quantitative predictions were made initially and have been monitored during operation. Expert opinion and judgement can be derived from previous experience and consultations. Table 5 gives an example of a systematic cross-analysis between project elements and the protected features in a Natura 2000 site. Project phase Project component Habitat 1 River Habitat 2 Riverine forests Habitat 3 Wet heaths Species 1 Fish Species 2 Invertebrates Species 3 Birds Construction Ponds Riverbed and river flow modification (xx m -length) Loss of area (xx m2) Loss of area (xx m2) Changes in species communities Disturbance, displacement of individuals. Loss of breeding habitat Buildings Loss of area (xx m2) Habitat loss and deterioration Roads Local changes in water flow Loss of area (xx m2) Habitat loss and deterioration Operation Fish feeding and treatments Water pollution by organic and chemical products Habitat quality alteration due to water pollution Disturbance, displacement of individuals Water abstraction Habitat alteration due to flow reduction Habitat degradation due to flow reduction Habitat degradation due to flow reduction Lighting Disturbance, displacement of individuals Disturbance, displacement of individuals Noise Displacement of individuals The assessment must be based on the best available scientific knowledge in the field. This means that the information must be complete and up-to-date. For this reason, it is often necessary to carry out field surveys in order to fill information gaps and collect precise data. This may involve, for example, prospecting the area (using sampling methods, censuses, inventories, etc.) to identify or confirm the precise location and distribution of natural features in relation to the planned activities of the plan or project under assessment, and their conservation condition. A prior desk study may be useful to review available knowledge and identify the information needs that warrant further field survey work. For instance, this can be useful practice when the desk study indicates that there are vulnerable habitats present which have an associated rare assemblage of flora and/or fauna, or that the area to be affected hosts species critical for the conservation objectives of the site. Data obtained from field surveys should provide an objective basis for the assessment process, which has to be carried out in view of the site-specific conservation objectives. For the field data to be complete, a sufficient timeframe has to be set, e.g. a one or more-year study that covers a whole vegetation cycle, taking into account the seasonality of the wildlife, or faunal surveys that may need to be repeated to confirm populations and trends over a period of time. For major developments such as motorways, railways, windfarms, ports, waterways, etc., which due to their scale and nature are expected to have significant effects on a site, field studies are almost always required. They will need to include detailed mapping of protected habitats or of breeding or resting places of species etc. (unless some of these surveys and studies have already been carried out recently, for example during the preparation or updating of a management plan or while assessing another major development project in the area). The impact should be quantified or recorded using parameters that make it possible to assess the scale and severity of the impact on the specific conservation objectives of the habitats and species significantly present on the site (see also box 7 in section 3.1.4 for indicators of significance) . This could include, for instance, parameters such as: — Area of the habitat or habitat of the species permanently lost (e.g. by clearing of vegetation or removal of suitable breeding/nesting sites) assessed against the habitat area on the site, at regional, national and biogeographical level (percentage of habitat area lost) and against the target set in the site-specific conservation objective (which may include a target for restoration); — Area of the habitat or habitat of the species affected (e.g. by pollution, noise, deterioration of other ecological conditions) assessed against percentage of the habitat area on the site, at regional, national and biogeographical level (percentage of habitat area affected) and against the target set in the site-specific conservation objective (which may include a target for restoration); — Size of resident and migratory species populations affected, assessed against the local, regional, national and international populations (percentage of population affected) and against the target set in the site-specific conservation objective (which may include a target for an increase in population size within the site); — Scale of impact (e.g. by pollution, noise, deterioration of other ecological conditions) on the quality of the habitat or habitat of the species or the survival of species affected, in view of their ecological requirements in the site as defined in the site-specific conservation objective (which may include a target for restoration). As already mentioned in the points above, when assessing possible adverse effects, the assessment should not only consider negative changes in the current status, but also changes that can prevent the achievement of the conservation objectives in so far as they require improvement of the current conditions. Assessing cumulative effects with other plans and projects Cumulative impacts can result from the successive, incremental, and/or combined effects of a development (plan, project) when added to other existing, planned, and/or reasonably anticipated developments (see also section 3.1.4, table 2 on the key steps for assessing cumulative effects on a Natura 2000 site). Examples of cumulative impacts include: — increased pollutant concentrations (particularly in water and soil), beyond levels compatible with the ecological requirements of the habitat or species protected in the site; — reduction of water flow in a watershed due to multiple withdrawals, below the level which is compatible with the ecological requirements of the habitat or species protected in the site; — interference with migratory routes or wildlife movement; — increased pressure on habitats and species in an ecosystem from different developments. Cumulative impacts encompass a broad spectrum of impacts on different geographical scales and timeframes. In some cases, cumulative impacts occur because a series of projects of the same type are being developed. Prime examples are: — when several hydroelectric projects are constructed or planned on the same river or within the same watershed; — when multiple oil and gas projects or mineral extraction projects are developed in close proximity; or — when a number of wind farms are constructed or planned within the same flyway or region. In other cases, cumulative impacts occur due to the combined effects of different types of projects in the same area, such as the development of a mineral extraction site, access roads, transmission lines, and other adjacent land uses. In some situations, different components of the same development are implemented and assessed separately, meaning that the cumulative impacts from these components should also be subject to a cumulative impact assessment. Other plans or projects that could, in combination with the plan or project under investigation, have a significant effect on a site must be taken into account during the appropriate assessment. For example, a proposed road will pass some distance from a Natura 2000 site and the disturbance it will generate (e.g. noise) will not significantly affect bird species protected in the site. However, if there are other existing or proposed projects or plans (e.g. a road on the other side of the Natura 2000 site), then the total noise levels from all these projects combined may cause a significant level of disturbance for those bird species (noise levels above what it compatible with the ecological requirements of the species). To note also that cumulative impacts could occur where impacted areas interact. An example of this would be where a proposed project is likely to reduce water levels in a Natura 2000 site. Although that resource reduction in itself may not be significant, if existing fertiliser and pesticide residues reach the site from a nearby intensive farming area, the lower water levels may mean higher concentrations of pollutants when run-off occurs, to an extent that the combined effect becomes significant, i.e. concentrations of pollutants beyond the levels which are compatible with the ecological requirements of the habitat or species protected in the site. ‘In-combination’ effects should already have been investigated at the screening stage (Section 3.2), and any other plans and projects that can act in combination should have been identified. The assessment at the screening stage may have been simplified, but, at the appropriate assessment stage, the identified impacts of other projects or plans that can act in combination with the plan or project being assessed should be properly evaluated. This requires quantifying and/or qualifying the magnitude of these other impacts and identifying the affected features of the Natura 2000 sites. As stated in section 3.1.4, the in-combination provision concerns other plans or projects that have been already completed, approved but not yet completed, or submitted for consent. In addition to the effects of the plans or projects that are the main subject of the assessment, it may be appropriate to consider the effects of already completed plans and projects, including those preceding the date of transposition of the directive or the date of designation of the site. The effects of such completed plans and projects would typically form part of the site's baseline conditions which are considered at this stage. Plans and projects that have been approved in the past but have not yet been implemented or completed should also be included in the in-combination provision. As regards other proposed plans or projects, in the interest of legal certainty it would be appropriate to restrict the in-combination provision to plans that have been actually proposed, i.e. for which an application for approval or consent has been submitted. At the same time, it must be evident that, when assessing a proposed plan or project, Member States do not create a presumption in favour of other not yet proposed plans or projects in the future. See further details in the Article 6 Guide – section 4.5.3. The geographical scope to use when looking at cumulative effects will depend on the type of plan or project and the habitats and species significantly present on the site. It could be, for instance, within a certain radius, on a catchment area basis, or along a bird migration route. It should however cover the entire geographic area in which all plan or project activities and their cumulative effects are likely to have implications on the conservation objectives of the Natura 2000 sites in question. Plan level assessments are particularly suitable for assessing cumulative and synergistic effects since they can pre-empt problems further down the line at the project stage, e.g. in the case of plans for specific sectors such as transport, energy, water management, as well as regional plans and strategies, land use plans, etc. In this context, it can be particularly useful to consult the environmental assessments of other existing plans and projects affecting the same area (SEA and appropriate assessment where available). The appropriate assessment carried out on these plans may also determine the scope for the appropriate assessment of individual components of the plan (projects) in terms of their cumulative effects. For example, when scoping the appropriate assessment of a mineral extraction plan, it may be useful to determine the range or extent to which the wider network of access roads to extraction sites may contribute to the cumulative impacts, e.g. in relation to habitat fragmentation affecting populations of species. Table 3 illustrates the sources that can provide information on other plans and projects that can give rise to cumulative effects. Tools to collate cumulative impacts, like databases recording the projects and plans to be considered, are helpful to streamline the assessment of cumulative effects. For instance, getting an overview of different activities is greatly facilitated if there is an up-to-date national or regional database, preferably including a dynamic map, which enables users to search all projects, including those still in the planning phase. In order for those databases to be useful for the appropriate assessment, competent authorities should aim to maintain the relevant documents online (e.g. impact assessment, mitigation measures introduced or conditions set for approval) also after permits are granted. Competent authorities (nature conservation, sectoral) should be consulted in order to collect information about the other plans/projects that should be considered during the assessment. Competent authorities can also contribute or support the assessment of cumulative impacts, as they have the best overview and knowledge about other activities across wider areas. They can also collect all relevant information and provide this to the project developers and consultants. The assessment of cumulative impacts may draw on information from a variety of sources including environmental studies and programmes, strategic, sectoral, and regional environmental assessments, project level environmental assessments, cumulative impact assessments from similar situations and targeted studies on specific issues. Expert advice can also be a good source of information on cumulative effects. A wide variety of methods and tools can be used to assess cumulative impacts, which usually also includes a scoping and an evaluation phase (see Figure 2 below). Source: European Commission, 1999. Guidelines for the Assessment of Indirect and Cumulative Impacts as well as Impact Interactions. Consultations, checklists, overlay maps, network and systems analysis can be suitable tools in the scoping exercise, which will identify the potential impacts to be looked at further in the cumulative impacts assessment. — Network and systems analyses are based on the concept that there are links and interaction pathways between individual features of the environment, and that when one element is specifically affected, it will also have an effect on other features that interact with it. — Spatial analyses use geographical information systems (GIS) and overlay maps to identify where the cumulative impacts of a number of different actions may occur, and identify impact interactions. It can also overlay a project’s effect on selected receptors, features or resources to identify where the impact would be greatest. — Sensitivity mapping can also be useful, as it may help predict potential cumulative impacts of certain activities on natural features that are vulnerable to the effects of those activities (see further details in section 4.2.2 of this guidance document) (31). — Expert panels can be formed to identify and assess cumulative impacts. Matrices can be used to evaluate impacts and to consider the cumulative impacts of multiple actions on a site or feature as well as interactions between impacts. — Modelling provides an analytical tool to quantify cause-and-effect relationships by simulating environmental conditions. This can range from air quality or noise modelling, to the use of a model representing a complex natural system. — Carrying capacity (32) analyses look at the accumulation of impacts against thresholds. However it may not always be possible to set the threshold or carrying capacity for a particular feature or receptor. Whatever methods are chosen, they should be adjusted to the information available for the analysis and provide, whenever possible, a quantitative estimate of cumulative impact. If qualitative estimates of cumulative impact are to be developed, they should be based on a consensual estimate of a panel of independent experts rather than on the opinion of an individual expert. A panel may also be useful and even necessary, for instance where cumulative effects to be assessed come from different projects, e.g. hydropower construction, dredging and irrigation on the same river. The method chosen does not need to be complex. The aim should be to present the results in a way that can be easily understood by the developer, decision-maker (i.e. competent authority) and the public. Governments can play a significant role by providing and implementing enabling frameworks to guide this work and help identify and manage cumulative impacts. Box 11 sets out an example of a step-by-step process for cumulative impact assessment. The process must be applied in a flexible way, i.e. the steps can be taken out of sequence and may need to be implemented iteratively, with some steps revisited in response to the results of others. Box 11 Example of a process for carrying out the cumulative impact assessment (CumIA) Step 1. Scoping — Identify the geographical boundaries and the timeframe of the CumIA; — Identify the protected habitats and species significantly present on the site and ecological processes to consider; — Identify other existing and planned plans and projects (and human activities) that do/would affect the natural features to be included in the CumIA; — Identify natural environmental drivers that also impact the condition of the features considered in the CumIA. Step 2. Assess cumulative impacts on the protected habitats and species — Collect available information on the impact of other plans, projects, activities and natural drivers on the site-specific conservation objectives set for the natural features in the site; — Estimate the cumulative impact on the protected features’ site-specific conservation objectives — i.e. the total impact on the protected features when the impacts of the plan or project under investigation are combined with other plans or projects. Step 3. Assess the significance of anticipated cumulative impacts — Assess the significance of the anticipated cumulative impacts on the natural features considered, taking into account its conservation objectives. For example, when the cumulative impact on the condition of the natural features approaches or exceeds a threshold for a certain attribute defined in the conservation objective of that feature, the impact is significant. Step 4. Managing cumulative impacts — Identify, when necessary, additional mitigation measures to reduce an estimated cumulative impact on the protected features (carrying out the tasks described in steps 2 and 3 will be necessary to assess the value of such additional mitigation).

← 3.2.1 · All articles · 3.2.3 →

Source: EUR-Lex (Cellar) · retrieved 2026-09-07