with this theory, we can look at issues of intergenerational equity raised by the way we use and care for our planet (Brown Weiss, 1989). I will then apply this theory to questions of water resources, examining future generations' rights to these resources and analyzing possible management strategies in the intergenerational context.
The relationship of our generation to other generations in the context of our natural system has two aspects. One is our relationship to other members of the human species—to the human community extended over time. The second is our relationship to the natural system of which we are a part. We should view both relationships in the context of a trust, in which the present generation is simultaneously a beneficiary and a trustee. Each generation is a beneficiary in its use of the planet for its own welfare and well-being and, at the same time, a trustee for conserving the planet for future generations. Similarly, as the most sentient of creatures in the natural system, we are at the same time a part of the system, entitled to use it and benefit from it, and a trustee for its conservation.
There are several models available for analyzing the relationship between our generation and future generations. Two prominent, opposing models are the ''preservation'' and "opulent consumption" models. The preservation model demands that everything be preserved as it is; the present generation, according to this view, has no right to change anything. This model is reflected in the English "natural flow" theory of water and in preservationist legislation regarding wilderness and other untouched areas. While the model may be appropriate for certain unique natural resources, it is not generally consistent with economic development and improved standards of living. The opulent consumption model encourages immediate consumption of resources, either because there may not be another tomorrow or because the higher level of consumption will make possible greater wealth for this and future generations. This model also has serious limitations; it does not recognize the need to use the environment on a sustainable basis, nor does it consider appropriate environmental costs in its economic calculations.