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Environmental Impact Design (EID)

Notes for a course in Landscape Assessment and Design

Environmental Assessment    Zoning Control   Development Control   EA Control   Landscape EA   The EID Process   Drawing Types  Web references

What is Environmental Assessment?

As the name implies, it is a technique for asssessing the environment. It is done with regard to development projects. ‘Environment’ comes from the French word for surroundings. All projects affect their surroundings. If they produce an improvement (better views, less pollution, more wildlife) we are all pleased to note the ‘beneficial side-effect’ or ‘positive externality’ or ‘positive environmental impact’. If, as happens more often, the affect on the environment is harmful, society has a right to protest - and a need to employ environmental designers.

There are two main types of legislation which are used to regulate the impact of projects on the environment:

  1. Zoning Regulations (including Land Use Plans and Town Plans)
  2. EIA Regulations

As the Fig shows, landscape and visual effects can be thought of as sub-categories of external effects [grammatical note: ‘affect’ means influence and ‘effect’ means cause but the distinction between the two is not always clear in environmental assessment].

Control by zoning  Top

Zoning plans reserve areas for defined land uses, but fail when they are exclusive.

Zoning laws were introduced in Germany in the late nineteenth century, to separate residential from industrial development. They produce what are now known as land use plans in Europe and as zoning plans in America. The existence of a plan confers legal certainty and fairness on contextual decisions. In much of North West Europe, a development will be approved if it accords with the land use plan and rejected if it does not. (Department of Environment, 1989:411). The British planning system is becoming more ‘plan-led’ but a land allocation on a local plan does not confer a legal certainty that planning permission will be granted.

Most of the large cities in Britain have been ringed by green belt zones since the 1950s. They have slowed the pace of development, driven up urban land prices, enriched some farmers and impoverished other farmers. But they have not halted the process of land development (Elson, 1986). Zoning plans fall into disrepute when they are subject to constant modification, and when powerful developers clutching fistfuls of gold can negotiate lucrative amendments. This is especially so when local people wanting to build apartments for their ageing parents cannot do likewise.

Another regrettable consequence of zoning plans is that they restrict land use diversity. In a natural habitat there is a web of interaction between individual plants and animals. The community gains mutual protection and re-cycles its by-products. Interactions of this type cannot occur if there is only one species in the habitat. Monoculture is inefficient, both in natural and human communities. If a residential area has a single use and a fixed density it will be occupied by people in a single socio-economic group. At 30 persons/hectare, they will probably have high-incomes, two children and two cars. This is less efficient than a mixed-use area with shops, businesses, schools and smaller homes for young people and old people.

Flexible zoning, as an alternative to singular zoning, is much closer to the patterns formed by natural habitats. Each habitat tends to have a dominant species (eg oak in an oakwood) and a wide range of associated species (birds, insects, fungi etc). One then finds a zone of transition where one habitat shades into another. Examples of the landscape zones which should guide contextual decisions were given in the previous chapter. They include zones for waterspace development, landform enhancement, habitat creation, greenspace, climate and scenery.

Development Control

Development control is a UK system

In the UK land development rights were nationalised by the 1947 Town and Country Planning Act. Since they it has been necessary to apply for planning permission before carrying out development, though certain forms of development are permitted without the need for an application under the General Development Order. In recent years the system has become more 'plan-led' in the sense that development municipal countillors and development control officers have to act in accordance with an approved local plan.


Control by environmental assessment Top

Control by EA fails when it is too pragmatic.

When it became apparent that the zoning system was not creating or protecting zones of environmental quality, it was supplemented by a second approach. Basically, the new idea was to assess each project as it arrived on the development agenda and discover what impact it would have on its surroundings. This became known as Environmental Assessment (EA) or Environmental Impact Assessment (EIA). [EA is the preferred term, partly because it leaves open the possibility that a development will have no impact whatsoever]. The concept of EA originated in America, partly because of its extra-rigid system of zoning. Planning control in some American states was much less comprehensive than in Europe and there was great public concern about the harmful affect which individual development projects were having on the environment. The National Environmental Policy Act (NEPA) of 1969 became a model for similar legislation throughout the world.

The key NEPA provision was that an Environmental Impact Statement (EIS) must be prepared for 'all major Federal actions significantly affecting the quality of the human environment'. The word 'actions' included building a house, planting a forest, felling a forest, laying a pipeline or carrying out a military exercise. The great value of the EA approach was that it included every influence of every project on every aspect of its context. Interaction matrixes were produced . Land users were prompted to consider the affects of each aspect of a development upon each component of the natural, social and spatial environment. For example, 'Soldiers defecating' was included for an EA of a military exercise in a wilderness area. For a road-building project, the component actions would include construction of a site office, removing vegetation, hiring local labour, stripping topsoil, deflowering local virgins, excavating subsoil, laying a base course, adjusting drainage patterns, and so on for ever. It was and remains a bonanza for environmental lawyers and scientists. A distinction can be drawn between:

- Strategic Environmental Assessment, which is concerned with the assessment of general policies, plans and programmes

- Project Environmental Impact Assessment, which is carried out by organisations proposing specific development projects.

The Florida Power and Light Company, in preparing EIA's for new power stations, had to submit 5mm (¼") thick report in 1970, a 75mm (3") report in 1971, a 150mm (6") report in 1973 and a 600mm (24") report in 1977. To deal with this escalation, restrictions were placed on the total length of American Environmental Impact Statements and on the categories of project for which they were required. The scope of the European Community directive on EIA was restricted to medium scale projects. Small-scale buildings and large-scale forestry or agriculture were excluded. A proposal for a large church surrounded by a new forest could fall within Schedule 2 Section 10 of the European Community directive, as a significant urban development project. Scientists could then identify negative impacts on fauna and flora. The hillside church would have an extensive Zone of Visual Influence. The cultural landscape would be adversely affected. It is likely that the project would not be approved. Control by EIA has an anti-development bias. The inbuilt assumption is that the status quo ought not to change. Control by EIA has become a highly structured procedure. The authors of a textbook on Environmental impact assessment identify fifteen steps in the process of EIA (Glasson et al, 1994:3):

  1. Project screening
  2. Scoping
  3. Consideration of alternatives
  4. Description of the project/development action
  5. Description of the environmental baseline
  6. Identification of key impacts
  7. Prediction of impacts
  8. Evaluation and assessment of significance
  9. Mitigation
  10. Public consultation and participation
  11. EIS presentation
  12. Review of the EIS
  13. Decision-making
  14. Post-decision monitoring
  15. Auditing

The EIA process is effective at permitting some projects and halting others. It is not as effective as it ought to be in securing improvements to a project design. This is identified as stage 9 in the above list but, as the authors note, mitigation 'is in fact inherent in all aspects of the process' (Glasson et al, 1994:137)

Environmental assessment for landscape  Top

Landscape architects have a particular interest in the EA process. According to Thompson, G.F. and Steiner, F.R. in Ecological design and planning (1997, page 3) ‘As a point of fact, Design with Nature (by Ian McHarg) laid the groundwork for the emergence of geographic information systems (GIS) and environmental impact assessments, which today dominate practice in both academic and public-policy spheres’. Other professions took the lead in EA work. Landscape architects can take it back. An EA project co-ordinator requires a broad understanding of the subject but an environmental assessor must be careful, for insurance reasons, not to stray outside their technical competence.[Liz Lake Associates comment that ‘The emphasis on Professional Indemnity Insurance forms has shifted from liability for built construction to how much EA you do and what’s your part in it. We have to be very careful not to get involved in anything outside our expertise (landscape, visual, nature conservation) unless we have people with special skills’.

If building yourself a house, a factory or a garden, you will think about your own needs. This is natural. It is what land owners and land users have always done. But as our planet becomes more crowded and more affected by its human population, we also have to think about the affect of land use development on other people and on our collective surroundings. In other words, we have to assess the impact of development on the environment. The technical term for this procedure is environmental assessment. Some of the impacts (eg noise, smoke and water pollution) are of more concern to scientists than to landscape designers. This is because scientists know how to measure some impacts (eg air pollution) and how mitigate them (by installing air filters). Other impacts (eg on scenery, vegetation and recreation) are of particular concern to the landscape profession. We can call them ‘visual and landscape’ impacts. The Landscape Institute published a book on this subject, which you should read. (Landscape Institute & Institute of Environmental Assessment (1995) Guidelines for landscape and visual impact assessment (London:E&FN Spon). You must also read Chapter 6, on Landscape, of Morris, P and Therival, R. Methods of environmental assessment. One of the old names for environmental impacts was ‘side-effects’ and the classic example was a smoky chimney (see Fig). A side-effect is described as positive if it benefits the environment and negative if it harms the environment. Good design can convert negative impacts into positive impacts. Economists often describe side-effects as ‘external effects’ or ‘externalities’, because their effect is external to the land use operation. 

Landscape impacts need to be assessed, one-by-one, and then mitigated, one-by-one. The end result of this process will be a landscape design. Were this not the case, there would be no need for landscape designers to become involved with landscape assessment. It could be done by geographers and environmental scientists. There are in fact two reasons for carrying out a landscape assessment:

  • to assess, from an environmental perspective, whether a development project should be allowed to proceed (‘authorised’ under EA legislation, ‘licensed’ under zoning controls or given ‘permission’ under planning legislation). We can call this Landscape (or Environmental) Impact Assessment.
  • to discover what improvements can be made to the project design (eg the site planning of an industrial complex) to improve, or mitigate, its impact on the environment. We can call this Landscape (or Environmental) Impact Design.

Landscape Assessment and Design can be viewed as a special approach to landscape design with the following characteristics:

  • it is analytical
  • it is sequential
  • it usually begins with a development proposal which someone else has formulated
  • it reaches out to treat ‘the environment’ as a set of clients, at least as important as the conventional client who merely owns the land and funds the development project
  • for each category of impact, one has to go through a survey-assessment-mitigation procedure.
  • after a set of mitigation proposals has been prepared, they should be welded into a comprehensive landscape design
  • it uses the term ‘mitigation’ when it should use the term ‘design’

For a conventional landscape design project, your client may be a Mrs Developer, who owns a company called Landspoil PLC. For a Landscape Assessment and Design project you may have another set of clients:

  • Mr Baron, who owned the site from 1330 to 1382
  • Mrs Hydrol, who cares deeply about water management
  • Mr Flora, whose roots go back a long way
  • Mrs Fauna, who is running all over the place
  • Mr and Mrs Neighbour, who live next door.

Each of these clients wants the landscape impact which affects them personally to be assessed and mitigated, usually with a single-purpose drawing. Note that the types of impact which concern us may be to do with the past, the present or the future. The Fig  shows a ‘layercake’ approach with categories for each of these time periods.

Environmental Impact Design is a most interesting approach to landscape design. It works by dividing a project development project into components, thinking creatively about each component, ‘adding up’ the components and applying an additional burst of creativity to produce the landscape design. I represented a process of this nature on pages 35 and 39 of City as landscape (Spons, 1996). It is shown in another way on Fig 4, with the individual ‘mitigation’ proposals being added together to generate the basis for a landscape design.

The layered approach to design  Top

Environmental Assessment provides another reason for adopting a ‘layered’ approach to design. It is set in the context of other reasons on page 57ff of City as landscape. A diagram showing a layered approach to contextual decisions is shown on page 115.

Jellicoe and the subconscious

Since writing City as landscape, I have written an essay on Jellicoe and the subconscious for the Landscape Institute monograph on Geoffrey Jellicoe (ed Shiela Harvey). Jellicoe is very interested in the ‘evolutionary’ layers of landscape experience which lie in man’s collective subconscious. He described them as Transparencies in the Guelph lectures on landscape design (1983).

EA in relation to landscape planning

A real weakness of the EA process in the UK is that it operates without the benefit of a framework of policy guidance. At some point in the future, projects will be environmentally assessed with regard to policies for landscape conservation and development. At present, the EA process looks ‘down’ to the past rather than ‘up’ to the future. The Countryside Commission’s Character Map of England could lead on to a policy framework for landscape planning.

The EID Process  Top

The approach of starting with an already-designed development project is very common in professional practice. Clients frequently approach landscape firms when they have encountered a landscape problem. [It is not so often that they come saying, ‘I have ten hectares and ten million pounds - have you any ideas?’.] For landscape assessment projects it is often the case that the developer has been refused planning permission or has been advised that the development project falls within Schedule 1 or Schedule 2 of the European Union’s environmental directive (See appendix to Guidelines for landscape and visual impact assessment).

The Environmental Impact Design process can be subdivided into as few or as many stages as one likes. There is a complicated chart on p 97 of Landscape and visual assessment. I see EA as having five main stages:

  1. Scoping study: this is a quick preliminary study which, as the name implies, seeks to identify the scope of the likely impact of a development project upon the environment. For example, it may tell you that the ‘impact on surface water runoff’ will be very significant but that there will be no significant impact on public rights of way. As the Fig suggests, it is a good idea to conclude the scoping study with a very preliminary mitigation proposal. An Interaction Matrix (Fig ASPECTS OF THE ENVIRONMENT / ASPECTS OF THE PROJECT) be useful as a checklist and as a way of representing the pattern of likely impacts graphically. It should have Characteristics of the Environment on one axis and Development Actions on the other axis. Fig 7 makes the same point with a Venn diagram. There is an example of an interaction matrix on page 47 of Landscape and visual assessment.
  2. Baseline study: the next stage is to establish the ‘baseline’ condition, for each aspect of the environment, before it is subjected to a fresh impact. A full survey of the site might take half a century. You are not going to do this: you are only going to investigate those aspects of the site which the scoping study has thrown up as likely to receive a significant impact. As the sequence of diagrams  shows, you have to define the baseline condition for each assessment. There are a number of standard drawing types which you should use for this purpose eg a Phase 1 or Phase 2 Habitat Survey, a Zone of Visual Influence (ZVI) drawing, a Landscape Character drawing. If the impact on habitat is a significant problem, you should produce a Phase 2 habitat survey.
  3. Impact assessment: the next stage is to make an assessment of each impact to discover whether it will be positive or negative. This assessment is a matter of judgement. But you should try to produce whatever evidence you can to support your judgement. The evidence might be statistics, a photomontage, cross-sections, sketches etc. Please be rigorous and ingenious. You are constructing an argument. Someday, the evidence may have to be presented at a public inquiry.
  4. Mitigation: the next stage is to make a mitigation proposal. Personally, I do not like the word ‘mitigation’. It suggests we are always trying to make development as similar as possible to the existing environment. In fact, development proposals can be Similar, Identical or Different to their surroundings. I have written an essay about this (‘Context and design’ in Turner, T., City as landscape, 1996). ‘Design’ is a better word.
  5. Landscape design: the final stage is to take an overview of the individual mitigation proposals and integrate them to produce a landscape design. You should also produce a diagrammatic ‘summary’ drawing to show what the individual mitigation proposals look like when you bring them together. You can think of this procedure as being a Pattern Analysis approach to design (see essays 3 and 4 in City as landscape). My own view is that this approach can produce proposals which are more relevant and more exciting than a traditional landscape design methodology (eg SAD).


In preparing drawings and explaining projects you should use as much of the accepted technical vocabulary as possible. Test yourself by discovering if you can wrote definitions of the following:

  • Determining Authority
  • Direct Impact
  • Non Technical Summary
  • Indirect Impact
  • Magnitude
  • Sensitivity
  • Impact Threshold
  • Tolerance
  • Scoping
  • Receptor
  • Mitigation

These and other terms are explained on pp90-3 of Landscape and visual assessment. See page 13 for the distinction between Landscape and Visual assessment. See also: the very full glossary in Morris and Therival (pp 335-341).


Survey and Evaluation  Top

The distinction between Survey and Assessment drawings predates the idea of environmental assessment. Please see Ian McHarg’s famous book on Design with nature. It has many examples of the pair. For example: a contour drawing merely shows survey information; an aspect drawing assesses this information to show the warmest south-facing slopes. In Environmental Assessment, one is assessing something different eg the extent to which the landform will be harmed by the proposed development.

At a public inquiry, the key issue is evaluation of impacts. One needs to evaluate both the magnitude and the significance of the impacts. Some impacts (eg ‘disturbance of a rare bird’) have a low magnitude but a great significance. Other impacts (eg ‘arrival of visitors on opening day’) have a great magnitude but a small significance. Specific design proposals can then be justified by reference to the evaluation. If, for example, there will be an impact on a water course one can, depending on the magnitude and significance of the impact argue for:

  • Replacement of the stream course elsewhere on site
  • Mitigation of the impact, by implementing a management plan for the stream
  • Compensation for loss of the stream by constructing a new wetland area


An audit is an ‘official examination of accounts’. Its normal use is for the annual examination, by accountants, of company accounts. Scientists had the idea that it would also be good idea to examine a company’s ‘environmental account’, to discover how much harm is being done to the environment (pollution, consumption of resources etc). This led to the term ‘environmental audit’. The EA process is extends the idea to development projects, but usually on a once-only basis. The term audit can be used to describe the process of monitoring a project on an annual basis. It is important to make a distinction between impacts of the development process and impacts after the project is established and in full operation. Since it might take 20 years for new planting to become an effective visual screen, one can define an ‘Opening Year’ or ‘Design Year’ for the date at which the Developer’s Proposal will have been completed.


Drawing types

There are a number of specific drawing types which are associated with the process of Environmental Assessment. You should try to make use of them where appropriate. If you analyse a landscape from a specific point of view, it is normal to couple the analysis with a proposal.

Zone of Visual Influence. A ZVI drawing always relates to a specific object. The drawing then shows all the points from which the object is visible. See page 49 & page 72 of Landscape and visual assessment for examples.

View envelopes: the envelope of land which can be seen from a defined viewpoint.

Scenic quality: you should use the Countryside Commission method to produce a map showing areas of quality graded from somewhere between 1-3 and 1-10. The method is explained on pages 38-9 of Landscape and visual assessment. People often call it ‘landscape quality’ but ‘scenic quality’ is the better term.

Viewpoints: see p 41 of Landscape and visual assessment.

Designations: a great deal of land is subject to official designations (eg Metropolitan Green Belt, AONB, SSSI etc). They should be mapped.

Land use: this relates to the use of land, not to its visual character. For example, a uniform area of moorland may be classified as ‘agriculture’ (if used by a farmer), ‘industry’ (if part-used as an electricity sub-station) and ‘recreation’ (if part of a country park).

Landscape character: show ‘zones of visual homogeneity’ (eg moorland, suburbia, coastal plain). [Note that p 42 of Landscape and visual assessment has examples of ‘Landscape types and ‘Landscape Character Areas’, which are somewhat confusing). Almost always, boundaries of landscape character areas should overlap.

Photomontage: see page 51, page 71, page 118 of Landscape and visual assessment.

Colour impact, colour strategy, colour planning: see Michael Lancaster’s Colourscape (eg pages 70 and 90). Also p 59 of Landscape and visual assessment.

Land Cover: the vegetation, and land use, which cover the land

Surface water runoff. see Appendix C (p317) of Morris and Therival on ‘The rational method of runoff prediction’.

Phase 1 Habitat Survey See Appendix E (p 325) of Morris and Therival ‘Outline of the NCC Habitat Classification’ and the Nature Conservancy Council’s own Handbook for phase 1 habitat survey.

Reminder: The above drawing types are very likely to find a place in an EA. But are not done for their own sakes. One should identify the need for them in a scoping analysis and then incorporate them into the argument, normally by using the specialised drawing as a ‘stepping stone’ to a mitigation proposal.

Web References The following book is available for  download: Visual Impact Assessment Foundations for Visual Project Analysis
by Felleman, Palmer and Smardon. See


DETR on Assessment on Landscape Assessment and on Habitat Assessment

GIS Unit at deMontfort University on landscape planning and use of GIS in habitat assessment

Middlemarch Environmental on Landscape Assessment and Design

Hampshire Historic Landscape Assessment

Australian discussion of Landscape Evaluation

US Environmental Protection Agency overview of landscape ecology Countryside Commission Press Releases