PARKS AND RECREATION COMMISSION MEETING AGENDA PACKET - July 10, 2025

Water Use Calculation Methodology Water use savings were calculated for each site using the State’s Model Water-Efficient Landscape Ordinance (MWELO) formula for Estimated Total Water Use (ETWU). See “Water Use Reduction” table on the next sheet for water use reduction calculations. Based on the aggregated limits of turf removal across the evaluated sites, a total of more than 54 million gallons of water is being used to irrigate 1.7 million square feet of turf. However, removing turf areas is only part of the solution. It doesn’t answer the question of what goes back in its place. The City requested two turf replacement scenarios. The first consisting of replacement with non-irrigated mulch (hereafter referred to as “Scenario A”) and the second consisting of replacement with drought-tolerant planting, referred to as “Scenario B”. Taking them one at a time, the installation of mulch in Scenario A does not require water to implement, however Scenario A still requires application of water to irrigate the existing trees to remain. Scenario B also requires application of water for drought-tolerant planting, albeit less than what turf requires. Water use was calculated again using ETWU assuming low water-use plants. To do this, the plant factor is changed to 0.20. These values are shown negative because they represent a reduction in water savings. The Net Water Reduction columns for Scenarios A and B subtract the Turf Replacement Scenario values from Total Potential Water Reduction. Converting all sites from turf to drought-tolerant planting would yield just over 40 million gallons per year in water savings. Source: California Department of Water Resources Chapter 2.7 Model Water Efficient Landscape Ordinance Definitions Reference Evapotranspiration ETo Used to determine the Maximum Applied Water Allowances so that regional differences in climate can be accommodated. ETo is expressed in inches per day, month, or year. Pleasanton ETo = 46.2 Inches/yr Conversion Factor .62 A conversion factor that converts acre-inches per year to gallons per square foot per year. .62 Plant Factor PF When multiplied by ETo, estimates the amount of water needed by plants. Plant factor range for very low water use plants is 0 to 0.1, low water use plants is 0.1 to 0.3, moderate water use plants is 0.4 to 0.6, and high water use plants is 0.7 to 1.0 Turf given a factor of 0.8 Drought Tolerant Plants given a factor of 0.2 Square Feet SF Per Site Conditions Irrigation Efficiency IE The amount of water beneficially used divided by the amount of water applied The irrigation efficiency for purposes of this ordinance are 0.75 for overhead spray devices and 0.81 for drip systems Overhead Spray= 0.75 TERMINOLOGY ABBREVIATION WHY IT’S USED HOW IT’S SHOWN PROJECT INPUTS Example Water Use Calculation: Amaral Park (7,885 S.F.) Estimated Total Water Use (ETWU) = (ETo)*(.62)*((SF*PF)/ IE ) Potential Water Use Reduction(ETWU) = (46.2)*(.62)*((7,885 * .80 ) / .75 ) ETWU = 240,915 gal./yr CITYWIDE TURF REDUCTION STUDY 5 / 47 CITY OF PLEASANTON © Copyrighted 2024 Callander Associates Landscape Architecture, Inc. WATER USE CALCULATION METHODOLOGY = (46.2)*(.62)*((7,885 * .20) / .75 ) Potential Reduction ETWU - Scenario A ETWU 240,915 - 955 = 239,960 gal./yr Potential Reduction ETWU - Scenario B ETWU 240,915 - 60,229 = 180,686 gal./yr = 60,229 Gal./yr ETWU ETWU A A B B A BScenario A : Mulch Only Scenario B : Drought Tolerant Planting Scenario Examples: Amaral Park Mulch Only Water Needs Net Water Use Reduction Net Water Use Reduction Drought Tolerant Planting Water Needs = (46.2)*(.62)*((125 * .20) / .75 )ETWU = 955 Gal./yrETWU Page 13 of 58