The estimated water use calculations for the project must be identified. The water use calculations must be certified by the landscape professional that it meets the water conservation in landscaping act requirements and bear the signature of the landscape professional as required by Business And Professions Code section 5615.
A. Water Efficient Landscape Worksheet: A project applicant must complete the "water efficient landscape worksheet" supplied by staff, which contains information on the plant factor, irrigation method, irrigation efficiency, and area associated with each hydrozone. Calculations are then made to show that the evapotranspiration adjustment factor (ETAF) for the landscape project does not exceed a factor of 0.55 for residential areas and 0.45 for nonresidential areas, exclusive of special landscape areas. The ETAF for a landscape project is based on the plant factors and irrigation methods selected. The maximum applied water allowance is calculated based on the maximum ETAF allowed (0.55 for residential areas and 0.45 for nonresidential areas) and expressed as annual gallons required. The estimated total water use (ETWU) is calculated based on the plants used and irrigation method selected for the landscape design. ETWU must be below the MAWA.
In calculating the maximum applied water allowance and estimated total water use, a project applicant must use the annual ETo value for El Segundo of 33.0. The annual ETo is found in the CIMIS reference evapotranspiration zones map, from department of water resources, published in 1999.
B. Water Budget: Water budget calculations must adhere to the following requirements:
1. The plant factor used must be from WUCOLS or from horticultural researchers with academic institutions or professional associations as approved by the California department of water resources (DWR). The plant factor ranges from 0 to 0.1 for very low water using plants, 0.1 to 0.3 for low water use plants, from 0.4 to 0.6 for moderate water use plants, and from 0.7 to 1.0 for high water use plants.
2. All water features must be included in the high water use hydrozone and temporarily irrigated areas must be included in the low water use hydrozone.
3. All special landscape areas must be identified and the water use for each area must be calculated using the "water efficient landscape worksheet" supplied by staff.
4. ETAF for new and existing (nonrehabilitated) special landscape areas must not exceed 1.0. (Ord. 1515, 12-15-2015)