Comprehensive water management scenarios for strategic planning

The assessment of the applicability and suitability of potential measures and instruments
is crucial in the strategic planning of water resources management. This paper presents a
methodology founded on scenario analysis for assessing potentially applicable water
management options in a regional context with respect to their efficiency, extent of
application, cost and environmental impact.
Formulation, analysis and evaluation of the different scenarios are performed through a
developed GIS-based Decision Support System (DSS). Selected options can be
simulated under varying availability and demand conditions, so as to monitor their
performance and define the extent of their applicability. The behaviour of the water
system is subsequently assessed and evaluated for each examined option in comparison
to a baseline scenario. The evaluation, based on computation of indicators and multicriteria
analysis, evolves around and reflects the principles of Integrated Water
Resources Management, Economic Efficiency, Environmental Sustainability, and Social
Equity. Temporal aggregation of indicator time series is conducted through the
computation of appropriate statistical criteria. Additional aspects that are addressed
concern the computation of the total cost incurred by water uses and provision of water
services, including Financial (Direct) costs, Resource costs, and Environmental costs
from pollution and (over) abstraction. Finally, indicator values can be used to derive a
Performance Matrix, which permits the ranking of the identified options and the selection
of those that are deemed most appropriate for the formulation of strategic plans.
Modelled management options pertain to four categories: Measures related with Supply
Enhancement, introducing new structural interventions to increase water availability;
Measures of Demand Management, aiming to control and limit water demands and
wasteful water use; Regional Development measures, affecting socio-economic
preferences and finally Institutional policies, such as alternative water pricing structures
and economic incentives.
The methodology is demonstrated through an application in the case of Paros Island,
Greece, where the developing tourist industry creates large seasonal peaks in water
demand, requiring the selection of appropriate mitigation methods. Scenarios were
formulated and evaluated for water management options identified by local Stakeholders
and proposed in existing management plans.