Stakeholder participation and multi-criteria decision making approaches to urban water supply planning in Iskandar Malaysia

Abstract

Stakeholder participation is a process where the stakeholder’s point of view is considered in the decision-making. The Multi-Criteria Decision-Making method (MCDM) is a technique in which all the decision criteria are weighted systematically and used to obtain the best result. This study applied stakeholder participation in complex decision-making of alternative urban water supply source using the MCDM technique. The alternative water resources considered in this study are desalination, reclaimed wastewater, groundwater and rainwater. The main objective of this study is to assign appropriate weightage to urban water supply management criteria through stakeholder participation and establish a priority ranking of different alternatives as the basis for developing an integrated urban water supply management guideline. From 200 criteria, initially listed from various literature, 100 criteria were selected and further reduced to six criteria and 59 Performance Measures by the stakeholders using Online Rating in Google Forms and Ranking by New Modified Graphical Innovative Method. The cost criteria score is the most unique as it gets the first importance in the Innovative method but scores the lowest in Online Rating. Criteria on environmental aspect score second in both questionnaires. Next, potential water supply alternatives were paired in different combinations and presented to the stakeholders in a hypothetical scenario and pairwise comparison were used for the evaluation. Most respondents ranked quality as the most important criteria, followed by hydrology and environment. Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE) which uses D-Sight Software was applied to get the final weightage of the alternative water supply. The pairwise comparison of hypothetical scenario result shows that rainwater harvesting and surface water score the highest preferences with a score of 20.12. However, rainwater harvesting had more potential with a medium scorc level compared to low surfacc water. This is followed by recycled wastewater, 20.01, groundwater, 19.92, and desalination falls last with 19.84, although the potential is high for the study area. However, the results obtained from the PROMETHEE method show that groundwater scored the highest (57.86), followed by desalination (54.74), rainwater harvesting (50.07), storage augmentation, 47.05 (business as usual) and recycling of wastewater (40.30). Even when the result is inconsistent, reflecting different opinions of stakeholders, the decision maker does not prefer business as usual and it is crucial to explore alternative water resources for better future water security. An integrated guideline which combines MCDM and stakeholder participation method was also successfully established through this research.