Wetlands are often particularly productive ecosystems, providing many important benefits. These benefits, sometimes described as goods and services, may be functions (e.g. groundwater recharge, flood control), uses (e.g. site for wood collection or research) or attributes (e.g. component of the landscape, religious significance). Many of the benefits provided by wetlands are essential to communities, industry and agriculture. Loss of wetlands may remove these benefits. This is not a case of "development vs. conservation", but simply a case of ensuring that the natural resources required for development and survival are maintained.
Degradation and destruction of wetlands is often carried out in the name of development. A lack of awareness of the important economic and social benefits that wetlands provide is a significant factor in this process. Development is often planned and executed sectorally (e.g. forestry, agriculture, infrastructure, resettlement) whereas wetland benefits almost always contribute to a multitude of sectors under the responsibility of different agencies. Adequate Environmental Impact Assessments (EIA) are required if projects are not to adversely affect wetland benefits. Many countries have now enacted legislation v/hich requires EIA to be carried out for projects which may cause significant environmental impacts.
A consideration of cross-sectoral impacts affecting the value of wetland benefits is needed for an EIA to be satisfactory. The best way of considering cross-sectoral impacts is by considering wetlands in a regional context, preferably based on watershed areas and hydrological units since wetlands are by definition dependent on water. Regionally based planning agencies are often in the best position to evaluate EIAs, because they are more easily able to consider cross-sectoral processes.
This manual may be used to scope EIA either from project-based or site-based (ecosystem) approaches, or both. It can be used by project proponents, regional planning boards, government departments, EIA consultants or anyone else who requires information about wetland benefits and the activities that may impact them. The manual also suggests mitigating activities that may be employed to reduce the impacts.
In order to be accessible to different user groups and to provide guidelines for site-based EIA, the manual can be used from several different starting points depending on the user's preliminary information. The primary aim of the manual is to assist in scoping EIA in wetlands by helping the user to make a list of wetland benefits which may be significantly impacted by the proposed development. Secondary aims are to assist project planning by indicating the scope of potential impacts on wetland benefits associated with locating projects in different types of wetlands, and indicating the scope of wetland benefits which may be required by certain projects. The manual is designed so that it can be used with either environmental or project information, or with both. The more information there is available, the more precise and complete the scoping.