Agenda - Public Works Committee - 01/16/2018

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November 10, 2017 Page 5 Ranking, Scoring, and Recommendation Two further steps were used to rank and score the communities with respect to the five criteria. The list of communities was sorted for each of the criteria: percent residential use, residential GPCD, peak ratio, total population growth, and number of new wells. Each time the list was ranked, a rank order was assigned to the communities, ranging from 1 to 94. Each time the list was sorted the values of the top 20 communities of that criteria was highlighted. Note that for most criteria, the communities were ranked in order from 1 to 94. However, for the number of new wells criterion, which was an integer from 0 to 9, there were multiple “ties” for each level. For example, the two communities with 9 new wells were both ranked “1”, then the three communities with 8 new wells were all ranked “3”, the communities with 7 new wells were all ranked “6”, etc. The overall ranking value (score) of each community was calculated as a sum of the five ranking numbers. Thus, the score values have a potential range from 5 (5 x 1) to 470 (5 x 94). A low score corresponds to a higher preference for assessment of water efficiency potential. The actual scores of the communities ranged from 67 up to 399. As currently calculated, each criterion carries the same weight in determining the overall score. Thought was given to the possibility of weighting the individual criteria in the calculation of the score. However, it was decided that any weighting scheme would impose some level of subjectivity into the selection process. Interestingly, a few tests of alternate weighting schemes resulted in only relatively minor changes in the final ranking. Depending upon which criterion had the most weight, one or two communities would be shifted in or out of the top 20 communities. The final (non-weighted) listing of communities by overall score is shown in Table 1. Based on this analysis, the top 20 communities in Table 1 are recommended as candidates for analysis of potential benefits of implementation of a water efficiency program as compared to expansion of water supply to meet future growth needs. It is anticipated that up to 5 communities will be decline the opportunity to participate in the next phase of this study. Therefore, the final analysis will be conducted on 15 of the potential 20 communities.