GROUNDWATER SUSTAINABILITY IN THE CONTEXT OF GENERAL SUSTAINABILITY CONCEPTS

Groundwater and surface water sustainability are subsets of the general sustainability concept. Sustainability is defined in a systems approach to set the stage for its application to groundwater for this symposium.

The definition: ”A sustainable process or condition is one that can be maintained indefinitely without progressive diminution of valued qualities inside or outside the system in which the process operates or the conditions prevail” is too general to be of practical value. This has been the drawback of other historic definitions such as the Brundtland and earlier reports. Terms such as indefinite maintenance, valued qualities, etc. must be specified in any practical definition. Sustainability must be defined as to what is to be sustained: stocks, rates, fluxes, economic value, etc., and in what context: biogeochemical, ecological, cultural and institutional or a mix. To determine if sustainability is invariant at different spatial and temporal scales, a holistic view is needed. Introduced here is the concept of the “noösphere” with its scientific, institutional and symbolic components as shorthand for socio-economic, political and cultural spheres. In order to determine actual or future problems, defined as gaps between the ideal or desired state and the actual or future state, sustainability must be quantifiable and measurable within and between categories. In complex cases indicators may be the only solution.

“Safe Yield” is a forerunner to the water sustainability concept but with similar difficulties. Its basic criterion is to maintain stock with zero or reduced impact. Hydrologic indicators on local scales such as stock (water levels), rate changes (drawdown), and fluxes are measurable. Is this still the case at larger scales? Socio-economic indicators are available: Water availability index, Water stress index, Water poverty index, Falkenmark flow units. These are discussed as global indicators of water availability on a per capita basis. Addressed here is how they can be translated to local and regional scales where continental water abundance is interspersed with areas of deficit such as on the North American Continent. How can these availability indices be translated into sustainability indicators that allow comparison, ranking, evaluation and possibly tradeoff management solutions?