Method for Comparing Alternative for SWSI

Home Browse Search

. C;OLORAl.X? r pppo, I??',E7FA??..+itTi?'EPM: C7f• • 1 VlkA.., RE?.?URCES ? S#otewid8 Wta#8r Supply lnitioia?re T?ait ? Method for Comparing Alternatives for Statewide Water Supply Initiative November 2003 Background To evaluate and compare different alternatives for a successful Statewide Water Supply Initiative (SWSI), a method has been developed based on a combination two approaches: (1) a traditional multi- criteria score card evaluation; and (2) stakeholder preference model. Multi-criteria score cards are typically used to evaluate different alternatives using a set of criteria, such as reliability, cost, environmental impact, location, etc. These different criteria are used to rank alternatives and aid in the decision-making process. Stakeholder preference models utilize individual preferences to identify the relative importance that people place on objectives (the reasons "why° we are developing alternatives) in the decision-making framework. Obj ectives Objectives will define the basic goals for SWSI. Examples may include: Meet Water Demands or Enhance the Environment. For each objective, there may be several sub-objectives that further define the intent of the objective. For example, under the objective Meet Water Demands, the sub-objectives might be: Meet Water Rights; Meet Agricultural Demands Where and When Needed; and Meet M&I Demands During Three Year 1950's Drought. Stakeholders will have difference preferences for these objectives, meaning that some objectives will have more or less relaiive importance than others. • Performance Measures For each objective and sub-objective, performance measures will be developed. Performance measures are indices that tell us how well each alternative is meeting a certain objective or sub-objective. For example, the performance measure for the sub-ob}ective of Meet M&I Demands During Three Year 1950's Drought might be the difference between water supply and demand for that hydrological- defined period. It is anticipated that many of the performance measures will be based on the State's DSS and existing technical reports and studies on water supply projects. Scoring Method Each alternative will perform differenfly for each of the sub-objectives (based on the performance measures). Since the performance will be measured in different units (e.g., meeting demands will be measured in acre-feet per year, while cost will be measured in dollars), it is necessary to convert all the performance into a set of common metrics. Using standardized approaches for doing this, all performance measures will be converted into a score of 0-10,10 always being best. By converting the different performance measures into a common metric, they can now be added together in order to arrive at a total score for each alternative. The total score can then be used to rank the alternatives from highest to lowest in terms of overall performance. However, before totaling the scores for each performance measure for each alternative, each stakeholder's preferences for the objectives will be applied. This will result in a set of unique rankings of alternatives for each individual stakeholder. In other words, stakeholder #1 will have a different ranking of the alternatives than stakeholder #6. By keeping track of each stakeholder's preferences and unique rankings, the alternatives can be compared more comprehensively to seek commonality and consensus among the alternatives. In past applications, this method has been used to successfully find alternatives that could be best supported by a diverse group of stakeholders with different views • and preferences. Lm ? S:\Meetings\CWCB BoardWlt comparison method - CWCB Bd 11-20-01dx 11l1112003