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10 <br />11 <br />12 <br />13 <br />14 <br />15 <br />16 <br />17 <br />18 <br />19 <br />20 <br />21 <br />22 <br />23 <br />24 <br />25 <br />26 <br />27 <br />28 <br />irrigated landscape area of 50,000 square feet without any Special Landscape Area (SLA= <br />0, no edible plants, recreational areas, or use of recycled water). To calculate MAWA, the <br />annual reference evapotranspiration value for Fresno is 51.1 inches as listed in the <br />Reference Evapotranspiration Table in Appendix A. <br />MAWA = (ETo) (0.62) [(0.7 x LA) + (0.3 x SLA)] <br />MAWA = Maximum Applied Water Allowance (gallons per year) <br />ETo = Reference Evapotranspiration (inches per year) <br />0.62 = Conversion Factor (to gallons) <br />0.7 = ET Adjustment Factor (ETAF) <br />LA = Landscape Area including SLA (square feet) <br />0.3 = Additional Water Allowance for SLA <br />SLA = Special Landscape Area (square feet) <br />MAWA = (51.1 inches) (0.62) [(0.7 x 50,000 square feet) + (0.3 x 0)] <br />= 1,108,870 gallons per year <br />To convert from gallons per year to hundred -cubic -feet per year: <br />= 1,108,870/748 = 1,482 hundred -cubic -feet per year <br />(100 cubic feet = 748 gallons) <br />(2) In this next hypothetical example, the landscape project in Fresno, CA has the same <br />ETo value of 51.1 inches and a total landscape area of 50,000 square feet. Within the <br />50,000 square foot project, there is now a 2,000 square foot area planted with edible <br />plants. This 2,000 square foot area is considered to be a Special Landscape Area. <br />MAWA = (ETo) (0.62) [(0.7 x LA) + (0.3 x SLA)] <br />MAWA = (51.1 inches) (0.62) [(0.7 x 50,000 square feet) + (0.3 x 2,000 square feet)] <br />= 31.68 x [35,000 + 600] gallons per year <br />= 31.68 x 35,600 gallons per year <br />=1,127,808 gallons per year or 1,508 hundred -cubic -feet per year <br />(d) Estimated Total Water Use. <br />The Estimated Total Water Use shall be calculated using the equation below. The sum of <br />the Estimated Total Water Use calculated for all hydrozones shall not exceed MAWA. <br />ETWU = (ETo)(0.62) P x A+SLAIE J <br />1J Where: <br />ETWU = Estimated Total Water Use per year (gallons) <br />ETo = Reference Evapotranspiration (inches) <br />PF = Plant Factor from WUCOLS (see Section 491) <br />HA = Hydrozone Area [high, medium, and low water use areas] (square feet) <br />SLA = Special Landscape Area (square feet) <br />0.62 = Conversion Factor <br />IE = Irrigation Efficiency (minimum 0.71) <br />(1) Example ETWU calculation: landscape area is 50,000 square feet; plant water use <br />type, plant factor, and hydrozone area are shown in the table below. The ETo value is <br />51.1 inches per year. There are no Special Landscape Areas (recreational area, area <br />permanently and solely dedicated to edible plants, and area irrigated with recycled water) <br />in this example. <br />23152.08101\8405361.1 <br />-12- <br />Plant <br />Hydrozone <br />Plant Water <br />Factor <br />Area (HA) <br />PF x HA <br />Hydrozone <br />Use Type(s) <br />(PF * <br />_(square feet <br />(square feet <br />1 <br />High <br />0.8 <br />7,000 <br />5,600 <br />23152.08101\8405361.1 <br />-12- <br />