75E - PH - WATER MANAGEMENT PLAN

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2015 URBAN WATER MANAGEMENT PLAN The Infrastructure Leakage Index (ILI) is a performance indicator developed from the ratio of Current Annual Real Losses (CARL) to the Unavoidable Annual Real Losses (UARL). CARL was developed as part of the workbook and explained as real losses above. UARL is developed on a per system basis with an equation based on empirical data, developed by IWA that factors in the length of mains (including fire hydrant laterals), number of service connections, average distance of customer service connection piping between the curb stop and the customer meter and the total length of customer service piping, all multiplied by average system pressure. The City received an ILI score of 0.15 which taken at face value is a very high score and indicates that real losses are well managed. This value suggests that the City's real loss volume is beneath the technically achievable minimum, which is possible but unlikely. This requires further field investigation of leakage if leakage detection and control practices are not extensively implemented and /or, given the Data Validity Score for some components in the Audit, further investigation /confirmation of entries such as water supplied /accuracy of supply meters, accuracy of customer meters, systematic data handling errors, and applicability of the default percentages applied in the audit. Apparent losses make up a significant portion of the City's total water loss at 80 percent; most of this was developed from default percentages provided by the AWWA Water Audit. Based on this information, the City can improve water loss by taking a closer look at apparent losses and developing a strategy to better quantify this data in the future. The overall Water Audit score can also be improved by meeting the standards AWWA has developed for each data point through clear City procedures and reliable data. The result of the AWWA Water Audit completed for the City as required by the 2015 UWMP is summarized in Table 2 -4. The water loss summary was calculated over a one -year period from available data and the methodology explained above. Table 2 -3: Water Loss Audit Summary (AF) 2.4 Demand Projections Demand projections were developed by MWDOC for each agency within the Regional Alliance based on available data as well as land use, population and economic growth. Three trajectories were developed representing three levels of conservation: 1) continued with existing levels of conservation (lowest conservation), 2) addition of future passive measures and active measures (baseline conservation), and 3) aggressive turf removal program - 20 percent removal by 2040 (aggressive conservation). The baseline demand projection was selected for the 2015 UWMP. The baseline scenario assumes the implementation of future passive measures affecting new developments, including the Model Water Efficient Landscape, plumbing code efficiencies for toilets, and expected plumbing code for high- arcadis.com 75E-26 2 -6