Board Meeting March 20, Facilitated by: Lisa Maddaus and Bill Maddaus

Transcription

1 Board Meeting March 20, 2013 Facilitated by: Lisa Maddaus and Bill Maddaus 1

2 Agenda Why Update Demand Factors? Review Historical Demands 1. Existing Customer Billing Consumption History 2. Influences on Historical Demands Forecasting Demand for New Customers Existing Lot Categories New Lot Categories Update to Demand Factors Next Steps 2

3 Demands Change Over Time Original Demand Factors were estimated back in early 1990s Based on limited number of accounts from 1980s Created estimated demand for production lots Demands are shifting due to influences such as: Housing density and people per household Lot size changes, aesthetics with more water features, irrigated area House design, plumbing fixtures & appliances Warming temperatures, drought frequency Economic up ( ) and downturns ( ) Future potential for recycled water Planning for the worst case scenario: Large lots with more features, irrigated area and people per household, warming climate, good economy 3

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8 Observed Variability from Average Demand for Typical Customer by lot type Table 2. Observed Percent Difference in Past Average Monthly Demand for Existing Lots Lot Type Maximum Observed Rolling Average ( ) Minimum Observed Rolling Average ( ) Percent Difference (Max to Min) ESTATE LOTS > 12, % CIRCLE LOTS % COTTAGE LOTS % ESTATE LOTS <12,000 (PRODUCTION LOTS < 6,500 SF) % HALFPLEX LOTS % TOWNHOUSE LOTS % MURIETA VILLAGE % VILLA LOTS NA Average 29% 8

9 Customer Category/Lot Type Table 3. Observations on Maximum Monthly Residential Demand (gal/day/acct) Historical Average Peak Months ( ) Historical Peak Month Minimum (2002) Historical Peak Month Maximum ( ) Percent Difference (2002 compared to 2005) Percent Difference (2002 compared to Average ) Minimum Month on Record ( ) Seasonal Irrigation Peak Month Ratio ESTATE LOTS > 12,000 SF 1,148 1,017 1,372 30% 18% CIRCLE LOTS ,042 22% 13% COTTAGE LOTS % 21% PRODUCTION LOTS < 6,500 SF % 12% HALFPLEX LOTS % 17% TOWNHOUSE LOTS % 25% MURIETA VILLAGE % 18% VILLA LOTS* NA NA Average 31% 24%

10 Customer Category/Lot Type Table 4. Actual Water Demand Usage by Customer Category (gal/day/acct)* Full Period Average ( ) Historical Annual Average (2005) High-Low Demand Range Percentage Difference (%) Demand Factors by Lot Type including 30% (Reference Year 2005) ESTATE LOTS > 12,000 SF % 827 CIRCLE LOTS % 638 COTTAGE LOTS % 550 ESTATE LOTS <12,000 (PRODUCTION LOTS < 6,500 SF) % 497 HALFPLEX LOTS % 413 TOWNHOUSE LOTS (OR APARTMENT UNITS) % 251 MURIETA VILLAGE % 189 VILLA LOTS % 164 COMMERCIAL LARGE 8,202 9,122 30% NA COMMERCIAL SMALL % NA COMMERCIAL IRRIGATION 1,419 1,763 30% NA PARKS 1,657 8,140 30% NA * For New Demand Factors refer to Table 7. 10

11 Water Budget Bottom-up Approach Indoor Demands 60 gallons per person per day 3 people per household 65,700 gallons per year indoor demand Outdoor Demands Driven by landscape coverage is the amount of irrigated area per lot or other water using outdoor features (pools, fountains, misters, etc.) Upper Range of applied water from average observed of 6.3 feet (Table 6) per year (ft/yr) Lower Range of 100% of the 30-year historical average reference evapotranspiration (watering requirements for healthy cool season turf grass 4-7 inches tall in full sun) for the California Irrigation Management Information System (CIMIS) for the Fair Oaks station at 50.5 inches (4.2 ft). Took the average of about 5.5 ft of applied water to an estimated irrigated area. 11

12 Updated Estimates for Demand Factors* Table 7. Water Demand Estimates for New Planned Lots (gpd/acct) Indoor Usage (gal/year/ acct) Landscape Coverage (sf/lot) Applied Water Estimate (Low End) (ft/yr) Applied Water Estimate (Upper End) (ft/yr)* Demand Factor Range based on New Planned Lot Categories (gpd/acct) Mid-point of the Range (gpd/acct) ESTATE LOT >24,000 SF 65,700 18, ,772-2,644 2,208 ESTATE LOTS > 12,000 SF 65,700 6, , PRODUCTION LOTS <10,500 SF 65,700 6, , PRODUCTION LOTS <8,500 SF 65,700 4, PRODUCTION LOTS < 6,500 SF 65,700 2, *Based on Best Available Information. Landscape coverage is assumed irrigation area per lot type. 12

13 Next Steps Release technical memorandum for public comment period from March 20 th April 17 th Meeting Review Commercial per Equivalent Dwelling Unit (EDU) and per Square Foot Factors presented on April 17 th Address Public Comments during April 17 th Meeting Address Board Questions Present final technical memorandum in May Board Meeting Adopt New Demand Factors 13

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