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15.50.035.   Water efficient landscape calculations.
   A.   Water efficient landscape calculations shall be prepared by and bear the signature of a professional appropriately licensed in the State of California to provide professional landscape design services; the signature shall be accompanied by a date and the following statement: "I have complied with the City of Fullerton Landscape Ordinance in preparing the Water Efficient Landscape Calculations."
   B.   The licensed landscape professional shall calculate the Maximum Applied Water Allowance (MAWA) for the total landscaped area to establish the upper limit of irrigation water that shall be used by the project annually. The MAWA shall be calculated using the formula and methodology established in Exhibit A to the Fullerton Landscape Ordinance. A separate worksheet shall be prepared for each point of connection. Seasonal calculations can be aggregated for an annual total.
      1.   The MAWA for landscaped areas shall be calculated using an Evapotranspiration Adjustment Factor (ETAF) of 0.7. The MAWA for special landscaped areas shall be calculated using an ETAF of 1.0.
      2.   The MAWA shall be calculated using a Reference Evapotranspiration Rate (ETo) in accordance with Table 15.50.35.A.
 
Table 15.50.035.A. Reference Evapotranspiration (ETo) Table
County and City
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Annual ETo
Orange
 
 
 
 
 
 
 
 
 
 
 
 
 
Santa Ana
2.7
2.7
3.3
4.6
5.3
5.7
6.0
6.0
5.2
3.4
2.6
2.0
49.7
 
* The values in this table were derived from the California Irrigation Management Information System (CIMIS) Spatial CIMIS data by zip code based on the monthly average for zip codes in the City of Fullerton.
   C.   The licensed landscape professional shall calculate the Estimated Applied Water Use (EAWU) for the total landscaped area to determine the total annual irrigation water need of the project as required to keep plants in a healthy state. The EAWU shall be calculated using the formula and methodology established in Appendix C to the Fullerton Landscape Ordinance. A separate worksheet shall be prepared for each point of connection. Seasonal calculations can be aggregated for an annual total.
   D.   The EAWU for the total landscaped area shall not exceed the MAWA.
      1.   The EAWU shall be calculated using a Reference Evapotranspiration Rate (ETo) in accordance with Table 15.50.035A.
      2.   The EAWU shall be calculated using the plant water use factor according to protocols defined in detail in the Water Use Classification of Landscape Species (WUCOLS) or from a source approved by the California Department of Water Resources. The plant factor ranges from 0 to 0.1 for very low water use plants, 0.1 to 0.3 for low water use plants, 0.4 to 0.6 for moderate water use plants, and 0.7 to 1.0 for high water use plants. The species factor shall be determined for each hydrozone based on the highest-water-use plant species within the zone.
         a.   The area of a special landscaped area (SLA) or water feature shall be defined as a high water use hydrozone with a species factor of 1.0 unless a plant factor according to protocols defined in detail in the WUCOLS is available. For calculation of the EAWU, the ETAF for SLA shall be calculated as the SLA plant factor divided by the SLA irrigation efficiency factor.
         b.   A temporarily irrigated hydrozone area, such as an area of highly drought-tolerant native plants that are not intended to be irrigated after they are fully established, shall be defined as a very low water use hydrozone with a species factor of 0.1.
      3.   The EAWU shall be calculated using an Irrigation Efficiency assumption by head type in accordance with Table 15.50.035B. Other values may be used when supported by manufacturer's specifications or landscape professional's calculations when derived from measurements and estimates of irrigation system characteristics and management practices.
Table 15.50.035.B Irrigation Efficiency (IE) Table
Irrigation Method
DULQ
DULH*
EU
IE**
Table 15.50.035.B Irrigation Efficiency (IE) Table
Irrigation Method
DULQ
DULH*
EU
IE**
Spray nozzles
65%
79%
 
71%
High efficiency spray nozzles
70%
82%
 
73%
Multi stream/Multi trajectory rotary (MSMT) nozzles
75%
85%
 
76%
Stream rotor nozzle
70%
82%
 
73%
Microspray
75%
85%
 
76%
Bubblers
 
 
85%
77%
Drip emitter
 
 
90%
81%
Subsurface drip
 
 
90%
81%
 
DU = Distribution Uniformity (the measure of the uniformity of irrigation water over a defined area)
*DULH = .386 + (.614)(DULQ)
** IE (spray) = (DULH)(IME)
** IE (drip) = Emission uniformity (EU)(IME)
(Ord. 3226 (part), 2016; Ord. 3134, 2009)