When preparing a project profile, it is not necessary to devote a lot of effort to considering environmental factors. However, it is important to be aware from the very beginning of the sort of factors that could lead to sustainability problems when full project preparation is undertaken.
Environmental sustainability deals with the impact of the proposed project on the natural resources and environment in the area of the project. If it is intended to use a small stream to irrigate a large area, the amount of water needed might be more than could be drawn from that source during the dry period of the year. As a result, the irrigation system could fail, or there could be insufficient drinking water available to communities downstream. Such a project would not be sustainable. Projects which result in the destruction of natural forests, mangrove swamps, wetlands or other natural areas are also likely to be unsustainable, as the impact of these changes may well damage the livelihoods of the communities in the area, and result in erosion and other damage to the environment.
It should also be remembered that many sources of financing for projects will not approve activities that lead to environmental damage, so although the project may seem very profitable, it will be impossible to obtain the required loans or grants to implement it.
There are projects that may cause environmental damage if poorly designed, but will not if the design is properly thought out. This often involves considering ‘mitigation’ measures that will reduce the environmental impact. An example might be a slaughterhouse producing much waste material, which would pollute the waters of the river into which the effluent is pumped. Here the inclusion of wastewater treatment tanks may permit the water to be purified before entering the river, and thus eliminate the problem.