Chapter 4 - The evaluation and display of environmental impacts of river basin development projects

I. Introduction
II. Economic development account
III. Environmental quality account
IV. Environmental evaluation
V. Display

I. Introduction

In the last few years a number of methodologies have been developed to evaluate environmental impact. Although exceptions occur, (McHarg 1969; Institute of Ecology, 1971), generally most are used to evaluate the impact of proposed projects and contribute little to the early planning activity¹. However, following the principles and procedures for planning water and related land resources established by the U.S. Water Resources Council, the U.S. Bureau of Reclamation (1972) produced a methodology with several useful aspects:

- It is undertaken during the planning process.

- It takes into account the fact that many adverse and beneficial effects of development can only be measured in other than economic terms and that some, no less important, cannot be quantified at all.

- It explicitly evaluates many of the environmental concerns heretofore dealt with only superficially.

- It includes an evaluation of impact under a "no plan" alternative.

- The information is displayed in a logical, organized manner that facilitates decision making.

¹ See also Appendix B for a short review of several Environmental Impact Assessment Methods.

This methodology must be modified to be applicable outside the United States because:

- It is based on two major objectives in planning the use of land and water resources. These objectives, national economic development and enhancement of environmental quality, required by United States law, have equal weight in developmental planning.

- Considerable emphasis is given to public participation which, for a large number of reasons, may not always be possible.

- It requires considerable descriptive information involving financial resources and time to gather the necessary information, which may be prohibitive.

Thus, the methodology of this chapter is an adaptation of the Water Resources Council's procedures and uses only two accounts for evaluating and displaying information on environmental costs and benefits of development projects:

- The Economic Development Account presents environmental impacts that can be evaluated financially, and

- The Environmental Quality Account displays environmental impacts that cannot be evaluated financially.

The geographic areas to be considered in the evaluation will vary according to the environmental feature of interest and how it relates to the project or program being considered. The Economic Development Account and the Environmental Quality Account should include the areas to be occupied by projects or programs and their zones of influence, including those downstream to the mouth of the basin.

II. Economic development account

The procedures for evaluating economic impacts are well known and will be mentioned here only when they are related directly or indirectly to questions of environmental quality. Details of specific methods for evaluating environmental effects in the Economic Development Account are presented in Appendix D. Certain general statements, however, should be noted.

For example, prices to be used in the evaluation should reflect the real exchange values expected to prevail during the period analyzed. In addition, care should be taken to see that the discount rate is established according to realistic economic conditions and valid economic concepts.

Although the period analyzed generally covers the time period during which the plan can be expected to serve a useful purpose or until further discounting will have no appreciable effect, consideration should be given to the long-term environmental effects which may extend beyond these periods.

Uncertainty, characterized by the absence of any known probable distribution of events, can be analyzed by using a sensitivity analysis and plans should be evaluated in terms of their sensitivity to both the available data and to future economic, demographic, environmental, and technological trends. A plan that is not implemented within a reasonable time after completion should be reviewed to make sure that it continues as the best alternative for achieving the objectives.

Beneficial effects in the Economic Development Account are the increases in the value and output from services and improvements in economic efficiency. A number of activities, such as flood control and prevention, floodplain management, drainage, prevention of sedimentation, land stabilization, and erosion control, contribute to developmental objectives through protecting and improving the productivity, use, and attractiveness of resources. From the viewpoint of their contribution to economic development, the effect of these activities on the output of goods and services is an increase in land productivity or a reduction in the cost of its use.

Recreation potential may also be evaluated in the Economic Development Account. As living standards are raised, once basic needs are met, the average person uses an increasing percentage of real income to fulfill leisure time activities, such as swimming, picnicking, boating, hunting, fishing, and other forms of outdoor recreation. With widespread ownership of automobiles and improvement in highways and public transportation, travel to distant public and private recreational areas becomes commonplace. Consequently, an increasing portion of recreational demand, especially that portion which is water-oriented, should be provided for by medium- and long-term river basin development planning.

River basin plans may include specific measures to enhance fish and wildlife resources with associated opportunities for their harvest as a commercial product as well as for recreation. Benefits to commercial fishing, hunting, and trapping may be increased and this increase may be determined by comparing values of future production with and without the plan.

Adverse environmental effects may result in adverse effects on economic development. Where a physical structure is necessary to obtain the desired objective, the adverse effects on economic development will include all cash expenditures for goods and services necessary for its construction and operation. In addition moreover, where nonstructural measures are used to meet the desired objective, the adverse effects on economic development will include the purchase of easements or rights-of-way and costs incurred for management arrangements or to implement and enforce necessary zoning and protective laws.

External diseconomies are adverse economic effects of a plan that are not reflected in market prices of project inputs and also should be included as costs. They result when provision of goods and services for one group necessarily result in an undesirable effect on another group, as when a plan reduces the output of a firm or when a plan has an adverse direct effect on consumption by individual consumers.

For example, the return flow from an irrigation project may create a salinity condition for downstream water users, forcing them to adopt costly water treatment practices. The reduction in output by a group of users (fisheries) which have their output processed by another firm (cannery) may result in an inefficient operation by the processing firm; or a plan may increase congestion or pollution, resulting in increased costs to consumers.

Another potentially significant environmental impact as a result of river basin plans undertaken in designated areas is in population distribution. Both positive and negative impacts may result. Contributions of a plan to a favorable population distribution and urban-rural balance are beneficial effects. However, urbanization and population migration created by a plan may cause social, cultural, and economic problems that will require costs for their melioration. Some of these costs should be assigned in the Economic Development Account.

III. Environmental quality account

As has been shown, some of the environmental effects of river basin development may be evaluated economically although they generally are characterized by their nonmarket, noneconomic nature. Whatever the case, an evaluation of these effects can still provide important evidence for formulating and judging developmental strategies, programs, and projects.

Beneficial environmental impacts are those that result from the management, preservation, or restoration of one or more of the desirable environmental characteristics of an area under study or within its zone of influence; adverse environmental impacts are those that result from actions leading to the deterioration of desirable environmental characteristics. To the degree possible, each of the major beneficial and adverse impacts should be quantified and displayed for the use of those who must make decisions about planning and developing river basins. This requires the use of criteria for describing the impact so that the various developmental alternatives may be compared. These are presented in Appendix D. In all cases, the importance of the impact will depend upon the nature of the environmental feature being impacted and the nature of the impacting action. These may be evaluated according to the following factors and comparisons made with and without the impacting action.

a) Quality. How valuable is the environmental feature? Comparatively speaking, how good are the services offered by this particular feature? Are they the best known?

b) Quantity. How much of the impacted environmental feature is there? Or, what quantity of contaminant will be released?

c) Human Influence. How much is the environmental feature used by human populations and for what ends? By whom?

d) Uniqueness. How rare or available is the environmental feature being impacted?

e) Degradation. How much will the impacting action degrade the environmental feature?

f) Reversibility. Are the results of the impacts reversible over the short-, medium-, and long-term?

g) Importance. Are there any impacts or environmental characteristics that are particularly dangerous or important?

IV. Environmental evaluation

The purpose of this section is to discuss a methodology for evaluating environmental impact and for displaying the results of that evaluation. Examples of the types of questions that need to be reviewed are given along with a short general description of representative environmental categories.

· Economic category

The economic environment consists of such things as currency, infrastructure, and goods and services as well as processes, such as marketing, saving, investing, industrialization, and construction. Two items should be mentioned because of their impact on environmental quality which have not been sufficiently discussed in the evaluation of river basin development projects. These are fossil fuel consumption and residual generation.

a) Fossil Fuel Consumption: Despite the fact that many river basin development efforts offer projects for the production of hydroelectric energy, there is generally also a large increase in the use of fossil fuels both for the construction of projects and as a necessary requisite for other projects, such as agricultural or industrial development. Given the increasing cost of fossil fuel energy and, in many developing areas, the scarcity of this resource, the influence of fossil fuel consumption should be evaluated.

b) Residual Generation: A great many river basin development projects result in the generation of residuals. These residuals take many forms and, in most cases, result in the contamination of air, water, and soils. Thus the production, disposition, and potential use of these residuals should receive an environmental evaluation for each project alternative.

· Social category

This is the human component of the environment and includes demographic characteristics, spatial distribution, culture, migration, physical and psychological health, employment, productivity, education, and nutrition.

a) Human health: Both the general health status and specific disease and health problems of the population should be evaluated. Specifically, investigations should evaluate the susceptibility of the population to specific diseases, the proximity of the population to health hazards or unhealthy conditions, and the incidence of contact with disease vectors or conditions involved in the transmission of diseases or health problems.

b) Population migration: Developmental projects can influence population migration i) by interrupting the traditional migration patterns of indigenous peoples; ii) by decreasing emigration from the development area because of increased opportunity and improved conditions within the area, and iii) by increasing the immigration for these same reasons. The impacts of these changes may be positive or negative and the short-term impacts may be different from the long-term impacts; all should be evaluated.

c) Green space and green belts have a function in human health, welfare, and public safety as well as providing transportation corridors and recreational opportunities.

d) Air quality includes the chemical, physical, and biological aspects of air. Of highest quality would be air that is free from any materials that adversely affect human and biotic communities.

e) Culture: Human cultures and life styles that contribute to the diversity of a population will be impacted, including the cultures of new and old immigrant groups as well as the indigenous peoples of an area. To a large degree the value of a given culture depends upon how that culture views itself and what its desires are, just as it's value depends upon how it is viewed by others in the nation or region. These viewpoints may result in objectives to assimilate a culture into the mainstream of a country or a region, or they may lead to efforts to protect that culture and its life style from certain destructive effects of development. Aspects of the culture that are particularly relevant include religious and ethical concepts, family structure, customs and mores, taboos and preferences; they also include the day-to-day activities that have proven successful over thousands of years of evolution. As a consequence, many things can be learned from a culture that is in equilibrium with its surroundings and these often can be adapted for development purposes. Because of this, the impact of development on the extant cultures of an area needs also to be evaluated.

· Archeologic/historic category

This includes those material remains, such as occupational sites, work areas, evidence of farming, hunting and gathering, burial sites, artifacts, and structures of all types which are evidence of human occupation and activities during prehistoric periods. In addition, it includes historic evidence concerning the origin, evolution, and development of a nation, state, region, or local area, such as those places where significant historical or unsual events occurred even though no evidence of the event remains, or places associated with important historic personalities. Given the isolated nature of archeological remains and their importance in reconstructing the past; and, given the fact that historic events are not repeatable, this category should receive a uniqueness evaluation as well as discussion on the mitigation of negative impacts.

· Natural resources category

This category includes the renewable and non-renewable resources, such as water, soils, forest, fish, wildlife, air, minerals, etc. It goes beyond this in that it takes into account the interacting components and processes of the ecosystems under study. Thus, evaluation should be made on entire ecosystems as well as on the individual components and processes of these ecosystems. The definition and evaluation of ecosystems are facilitated by mapping the area's important life zones and through the use of conceptual models.

a) Terrestrial and aquatic ecosystems: Natural ecosystems can be broadly classified as terrestrial or aquatic and the ecosystem itself should be evaluated according to quantity, quality, human influence, uniqueness and reversibility of impact; critical areas or concerns and should be flagged.

b) Flora: This sub-category includes terrestrial, submerged, and emergent plants as individual species, as stands of individual species, and as communities of associated species.

c) Fauna: Both aquatic and terrestrial fauna can be broken into several important subgroups and may be discussed as subunits except where an individual species is of importance. Possible subunits are: threatened species, large animals, fur bearers, water fowl, other birds, reptiles, and amphibians, fish, crustaceans, mollusks, insects, and others. In addition to the individual wildlife species, the habitat of these species should be considered.

d) Edaphic: This sub-category includes soils or proto-soils and their applicability for the many agricultural, urban, industrial, and protective uses.

e) Geologic/topographic: This sub-category covers areas of geologic importance as future mineral sources as well as those areas of interest for the study or display of the earth's development, and for recreational purposes. It should include such things as fossil beds, potential ski slopes, caves, geothermal energy sources, areas having scenic values, and hazardous areas, such as those with severe incline and subject to landslides or mudflows, etc.

f) Water quality: This category includes the chemical, physical, and biological aspects of fresh, brackish, and salt water with respect to its suitability for a particular use. Of highest value would be water quality better than that which is needed for expected uses. The effects of a project on water quality may extend well beyond the immediate project area. Therefore, the total area under evaluation should be carefully considered in order to measure the cumulative environmental effects of all proposed actions.

V. Display

The display of these evaluations may be accomplished using a simple table format indicating the various project alternatives across the top and specific descriptions of the environmental categories to be impacted and the criteria along the right hand edge. Quantitative and qualitative evaluation summaries of these impacts are then presented within the table. Because each planning activity will be different, the planning team should develop its own format. Table 1, on page 40, is presented as an example to help understand the evaluation and display methodology.

Title: Social-economic development plan for "Valle de San Juan."

Time Frame: 50-year life of project.

Objective:

1) Raise production of horticulture crops in the area along the San Juan River by 40 percent. Decrease flooding costs by 20 percent.

2) Maintain productive capability of any rare, endangered, or economic species of flora or fauna. Conserve, where possible, important historic and cultural patrimony of the area.

Alternative A: Raise height of existing dam by 5 meters and build canal from existing reservoir to supply secure source of irrigation water to 15,000 hectares of cropland. Provide for full control of river.

Alternative B: Extend existing canal 10 kilometers and build additional small scale diversions to provide sufficient secure water for 9,000 hectares of cropland and water that is secure for 85 percent of all years on record for an additional 7,000 hectares. Include the maintenance of a unique prehistoric dwelling site and riverine ecosystem that would be flooded by increasing the reservoir area; plan for flood plain zoning and a reforestation project upstream to control flooding.

Table 1. Display of qualitative and quantitative effects of hypothetical socio-economic development for the Valle de San Juan