Project applicant may elect to submit a water budget calculation for the landscape project. A water budget must be completed by a certified professional who is authorized by the State of California to complete a water budget. Water budget calculations shall adhere to the following requirements:
A. All special landscape areas shall be identified and their water use included in the water budget calculations (Appendix B).
C. Maximum applied water allowance shall be calculated for each project using the formulae outlined in Table 14.15.070: MAWA Calculation.
Table 14.15.070: MAWA Calculation
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1. For existing non- rehabilitated landscapes > 1 acre that have dedicated irrigation meters. | MAWA= (ETo) (0.62) (LA) (0.8) |
2. For all new and rehabilitated landscapes | MAWA = (ETo) (0.62) [(ETAF x LA) + (1-ETAF x SLA)] |
Where:
MAWA = Maximum Applied Water Allowance (gallons per year).
ETo = Reference Evapotranspiration (inches per year).
0.62 = Conversion Factor (acre-inches to gallons).
LA = Landscape Area (square feet).
0.55 = Reference Evapotranspiration Adjustment Factor (ETAF) for residential areas.
0.45 = Reference Evapotranspiration Adjustment Factor (ETAF) for non-residential areas.
1-ETAF = Additional Water Allowance for SLA.
SLA = Special Landscape Area (square feet).
D. Estimated total water use (ETWU) shall be calculated for each hydrozone using the equation below. The sum of the ETWU calculated for all hydrozones shall not exceed the MAWA calculated using the formula above.
ETWU = (ETo)(0.62) (ETAF)(Area)
Where:
ETWU = Estimated Total Water Use per year (gallons).
ETo = Reference Evapotranspiration (inches).
0.62 = Conversion Factor.
Area = Total Landscape Area (square feet).
(Ord. 16-2142 (part), 2016)