Section 3 - Land Use, Population, and Water Demands. Section 3

Transcription

1 Section 3 - Land Use, Population, and Water Demands Section 3

2 SECTION 3 DEMANDS LAND USE, POPULATION, AND WATER This section describes the existing water demands, the population projections, and the projected future water demands for EVWD s service area. The future water demands are calculated based on population through year System build out demands are calculated based on land use information obtained from General Plans and water duty factors developed for various land use types. This section includes a discussion comparing the growth projections developed for this WSMP and EVWD s Wastewater Collection System Master Plan. A discussion on the impact of water conservation practices within the EVWD service area on future demands is also discussed. 3.1 Historical Water Production and Peaking Factors The historical water production for the period 2009 through 2012 along with the maximum month production (MMP) is presented in Table 3-1. The average annual water production in this period is approximately 21,454 acre-feet per year (AFY) with the highest production occurring in 2009 (22,722 AFY) and the lowest production in 2010 (20,663 AFY). The MMP peaking factors range from 1.45 to 1.5, which are typical values for water systems of this size in Southern California. Table 3-1 Historical Water Production Calendar Year Annual Average Average Month Maximum Month MMP (2) (AF) (AF) (AF) (1) Peaking Factor ,722 1,894 2, ,663 1,722 2, ,637 1,720 2, ,792 1,816 2, Average 21,454 1,788 2, Maximum 21,136 1,761 2, (1) AF = acre-feet (2) MMP = Maximum Month Production Average day demand (ADD) is a baseline for computing peaking factors. The maximum day demand (MDD), peaking factor and peak hour demand (PHD) factors are used to scale up the ADD to estimate MDD and PHD. These estimated MDD and PHD are the demand conditions used to size water distribution system pipelines and facilities. Historical monthly and daily production data are used to calculate these peaking factors and are presented in Table 3-2. The PHD peaking factor is discussed in Section 5 of this report. Project Number: February 2014

3 Section 3 Table 3-2 Historical Daily Demands and Maximum Day Peaking Factors Year ADD (mgd) MDD (mgd) MDD Peaking Factor Source: Historical Production Records (EVWD, 2013) The MDD peaking factors (MDD/ADD) varied between 1.6 and 1.8 over four previous years. These values are representative of a system that has a significant percentage of commercial and industrial water demand that is fairly uniform throughout the year. A conservative peaking factor value of 1.8 was selected as the MDD/ADD ratio, which is a value similar to other water utilities and commonly accepted industry standards. 3.2 Historical Water Consumption Yearly water consumption information is obtained from EVWD for the period 2003 through This data is summarized in Table 3-3 and depicted on Figure 3-1. Table 3-3 Historical Potable Water Consumption Year Average Annual Consumption (MGD) Average 19.3 Source: Historical Consumption Records (EVWD, 2013) Figure 3-1 shows the historical consumption for the periods. As shown on Figure 3-1, the total average water consumption increased to approximately 22 mgd in Since then, due to the economic downturn associated with the collapse of the housing market, water consumption has progressively declined. In 2010, the total average water consumption was 16.6 mgd, approximately 30 percent lower than the 2007 consumption. Overall water consumption seems to have stabilized in 2011 before increasing to approximately 18 mgd in Project Number: February 2014

4 Section Consumption (MGD) Figure 3-1 Historic Water Consumption in EVWD s Service Area The difference in volumes between water produced and water consumed is defined as unaccounted-for water, or the water losses within a system. Unaccounted-for water may be attributed to accounting and metering errors, leaking pipes, unmetered water use, water theft or any other event causing water to be withdrawn and not measured, such as reservoir overflows or leakage, hydrant flushing and fire-fighting. Average percentages of unaccounted-for water per year are shown in Table 3-4. Year Table 3-4 Unaccounted-For Water Water Produced (AF) Water Consumed (AF) Unaccounted-For Water (%) ,700 21,100 7% ,663 18,600 10% ,600 19,000 8% ,800 20,100 8% Average 21,400 19,700 8% Source: Production and consumption values provided by EVWD staff. Year Project Number: February 2014

5 Section Population Projections for EVWD s Service Area Population within EVWD s service area is utilized to analyze existing and future water needs. The population data are obtained from the following sources: United States Census Bureau San Bernardino Association of Governments (SANBAG) California Department of Finance Additional details regarding the existing and future population for EVWD s service area are presented in the following paragraphs Baseline Population Year 2010 Population for year 2010 for EVWD s service area is considered to be representative of the baseline population. The 2010 population serves as the basis for future water demand projections and for the evaluation of water conservation effectiveness. Population within the service area is estimated by analyzing 2010 census block information which is publicly available from the United State Census Bureau. Population estimates are calculated for each census block located within the service area. For census blocks partially located within the service area, the estimated population is adjusted based on the percentage of the census block area located within the service area. Census blocks are also visually inspected against aerial imagery to validate the adjustments made for blocks that are partially located within the service area. The 2010 population within the service area is 97,001. Table 3-5 summarizes the 2010 baseline population for EVWD s service area. Table 3-5 Baseline Population for EVWD s Service Area 2010 Source Population (1) 2010 Population within the Service Area - Census Blocks completely within EVWD Service Area 97,057 Adjusted 2010 Population within Census Blocks that partially overlap Service Area 2,821 Total unadjusted 2010 population within Service Area 99,878 Population Adjustments Eastwood Farms Annexation 2010 Population 375 Baseline Gardens Annexation 2010 Population 2,502 Total Population within recently Annexed Areas 2,877 Total Baseline 2010 population within Service Area minus population within Annexed Areas 97,001 (1) Population data are obtained from publicly available information from the United State Census Bureau (2010). Project Number: February 2014

6 Section Population Estimates from Other Sources MWH reviewed population estimates for EVWD s service area developed as part of other studies such as the 2010 Regional Urban Water Management Plan (RUWMP), the 2013 Water Use Efficiency Plan, and the 2013 Wastewater Collection System Master Plan. MWH also estimated population within the service area based on information available from the California Department of Finance. Findings from these reviews are summarized in Table 3-6. Table 3-6 Population from Other Sources Source 2010 Population 2013 Water Use Efficiency Plan (1) 63,055 California Department of Finance (2) 79, Draft Wastewater Collection System Master Plan (3) 93,500 (1) Kennedy/Jenks Consultants estimate for the 2010 population for EVWD s service area. (2) MWH s estimate for 2010 population is based on the number of persons per household and the number of service connections. The number of service connections in 2012 is estimated to be 23,126. Per the California Department of Finance s estimates on Population and Housing for 2012, the number of persons per household in the City of Highland is Per the 2012 estimates, the number of persons per household in the City of San Bernardino is (3) Black and Veatch s estimate for the 2010 population for EVWD s service area based on the 2008 Regional Transportation Plan, SANBAG s Traffic Analysis Zone (TAZ) data, and the U.S. Census. As shown in Table 3-6, there is significant variation in the population estimates documented in other studies reviewed by MWH. MWH s estimated 2010 population of 97,001 is approximately 3.7 percent higher than the estimate used in the 2013 Wastewater Collection System Master Plan and approximately 53 percent higher than the estimate used in the 2013 Water Use Efficiency Plan. EVWD reviewed these estimates and directed MWH to use MWH s estimate of 97,001 as the baseline population for EVWD s service area Population Projections for EVWD s Service Area Population forecasts developed by SANBAG form the basis of the projections developed by MWH for EVWD s service area. MWH developed population projections for the following four scenarios: Scenario 1: SANBAG Projections through year Assumes growth in the service area effective Scenario 2: SANBAG Projections from 2016 through No growth in the service area until Scenario 3: SANBAG Projections through year All major developments are constructed between year 2015 and year Scenario 4: SANBAG Projections through year All major developments are constructed between year 2020 and year Scenarios 3 and 4 assume that growth associated with the major developments are not included in the SANBAG projections. Figure 3-2 shows the population projections for these scenarios. Project Number: February 2014

7 Section 3 150, ,000 Population 130, , , ,000 90, Year Scenario 1 - SANBAG Projections Scenario 2 - No Growth, SANBAG Scenario 3 - Development , SANBAG Scenario 4 - Development , SANBAG Figure 3-2 Population Projections for EVWD s Service Area The projections range from approximately 125,000 people by year 2035 in Scenarios 1 and 2 to approximately 142,000 people by year 2035 in Scenarios 3 and 4. Scenarios 1 and 2 represent a 30 percent increase in population from the baseline or year 2010 conditions. Scenarios 3 and 4 represent a 46 percent increase from the baseline or year 2010 conditions. Populations for Scenarios 3 and 4 are different from Scenarios 1 and 2 as they include the following proposed developments summarized in Table 3-7. It cannot be verified whether populations for these developments are captured in the population projections developed by SANBAG. There is no publicly available information regarding the timing of these potential developments. Table 3-7 Population Estimates for Proposed Developments within EVWD s Service Area Proposed Developments Estimated Population at Build Out Harmony 11,989 Arnott Ranch 248 Highland Hills Ranch 1,650 Greenspot Village and Marketplace 2,800 Total Population 16,686 Source: Population for Harmony is estimated by MWH based on a review of RBF Consulting s Study for the Harmony Development. Populations for the other developments are estimated by MWH based on information presented in Section 2 of Black and Veatch s Draft 2013 Wastewater Collection System Master Plan. A comparison between the population estimates developed by MWH and the population estimates presented in Black and Veatch s 2013 Wastewater Collection System Master Plan are summarized in Table 3-8. Project Number: February 2014

8 Section 3 Table 3-8 Population Estimates for Proposed Developments within EVWD s Service Area Population Range MWH Estimate Black and Veatch Estimate (1) Low End 124, ,300 High End 141, ,700 (1) Population estimates obtained from the 2013 Wastewater Collection System Master Plan Existing Per Capita Water Use Water production within the service area has declined over the past few years primarily due to the economic recession. In order to avoid using a year with lower than average production, existing per capita water use for EVWD s service is estimated based on an average water production for the 2009 through 2012 period. This information is presented in Table 3-9. Table 3-9 Existing Per Capita Water Use for the Service Area Year Annual Production (Million Gallons) Production (Gallons Per Day) ,404 20,285, ,733 18,446, ,725 18,423, ,101 19,454,958 Average Production (gallons per day) 19,152,603 Per Capita Demand (gallons per capita per day) = Average Production/Baseline Population 197 Source: Production data provided by EVWD staff. As shown in Table 3-9, MWH estimates that the existing per capita water use is approximately 197 gallons per capita per day (gpcd). This is approximately 43 percent lower than the 10-year base daily per capita water use reported in the 2010 RUWMP. Based on a review of the 2010 RUWMP, it is observed that the population differences explained previously in this section resulted in a higher estimate of per capita water use for EVWD s service area for the RUWMP. It is recommended that the basis for the RUWMP per capita values be reassessed in light of the differing population values as it affects EVWD s compliance with the requirements of Senate Bill SB x Future Per Capita Water Use due to Conservation Per capita water use for future customers is assumed to be lower than for the existing customers in the service area due to the impacts of water conservation policies. Per capita water use for residential customers is estimated to be 130 gpcd while per capita water use for commercial, industrial, and institutional customers is estimated to be 42 gpcd. Table 3-10 presents the details of these estimates. The future per capita water use of 172 gpcd represents 13 percent conservation from the existing per capita water use of 197 gpcd. The estimates for future per capita use are consistent with Method 2 for calculating Compliance Water Use Targets published in the guidebook for the 2010 UWMP. Project Number: February 2014

9 Section 3 Table 3-10 Future Per Capita Water Use for the Service Area No Parameter Value A Per Capita Water Use for Residential Customers Average Lot Size for Single Family Residences for EVWD s Service Area 10,000 square feet B Assumed Average Irrigated Area 50% 5,000 C Estimated Irrigated Area (A x B) square feet D ETo (based on CIMIS data) 55.6 inches E Plant Factor (based on the Highland Landscape ordinance for a mix of turf and low to moderate water using plants) 0.7 F Estimated Water Use (C x D x E x 0.62 x 7.48/0.8) 94,015 gallons G Persons per dwelling unit (Estimates for the City of Highland) H Per Capita Water Use (F/365/G) 75 gpcd I Indoor Water Use (Target Indoor Water Use per Method 2 of the UWMP) 55 gpcd J Total Residential Water Use (H+I) 130 gpcd K Per Capita Water Use for Commercial, Industrial, and Institutional Customers Average CII Water Use 4,532,540 gpd L 2010 or Baseline Population 97,001 M CII Water Use (K/L) gpcd N 10 percent savings on CII Water Use (0.1 x M) (per Method 2 of the UWMP) gpcd O Total Commercial, Industrial, and Institutional Water Use (M - N) 42 gpcd P Per Capita Water Use for Future Customers 172 gpcd Project Number: February 2014

10 Section Demand Projections for EVWD s Service Area (Population Methodology) Future water requirements for EVWD s service area are estimated as the product of the population estimates and the per capita water use discussed earlier in this Section. Per capita water use for existing customers is assumed to be 197 gpcd. Per capita water use for future customers is assumed to be 172 gpcd. Demands based on population for EVWD s service area are presented on Figure ,000 Demand in Acre-Feet 30,000 28,000 26,000 24,000 22,000 20, Year Scenario 1 - SANBAG Projections Scenario 2 - No Growth, SANBAG Scenario 3 - Development , SANBAG Scenario 4 - Development , SANBAG Figure 3-3 Water Demand Projections for EVWD s Service Area (based on population) The projections range from approximately 27,000 AF by year 2035 in Scenarios 1 and 2 to approximately 31,000 AF by year 2035 in Scenarios 3 and 4. Scenarios 1 and 2 represent a 25 percent increase in population from the baseline, or year 2010 conditions. Scenarios 3 and 4 represent a 43 percent increase from the baseline, or year 2010 conditions. Demands for Scenarios 3 and 4 are different from Scenarios 1 and 2 as they include the following proposed developments which are summarized in Table Project Number: February 2014

11 Section 3 Table 3-11 Demand Estimates for Proposed Developments within EVWD s Service Area Proposed Developments Estimated Demand at Build Out (AFY) Harmony 3,168 Arnott Ranch 36 Highland Hills Ranch 240 Greenspot Village and Marketplace 539 Total Demand 3,982 Source: Demand for Harmony is estimated by MWH based on a review of RBF Consulting s Study for the Harmony Development. Demands for the other developments are estimated by MWH based on information presented in Section 2 of Black and Veatch s 2013 Wastewater Collection System Master Plan 3.5 Water Demand Projections Land Use Methodology Existing and future production requirements for EVWD s service area are estimated based on development projections, land use classifications, and water duty factors. A water duty is the average water use of a given land use type (in gallons per day per acre). Establishing water duty factors for EVWD s service area requires consumption data within the system, locations of water meters, and existing and future land use designations. The development of water duty factors using GIS (Geographic Information System) software are presented in the following paragraphs Assigning Average Demand and Land Use Types Water consumption data and the spatial location of water meters in the system are used for establishing existing water duty factors. Using GIS processes such as geocoding, a link is established between the spatial location of the meters and the water consumption data. A threeyear average ( ) demand is developed for these meters. General Plan Land Use and Existing Land Use shapefiles are obtained from the SANBAG website. Based on their spatial locations within the service area, a land use type is assigned for each meter. Land use designations are also assigned to all parcels within EVWD s service area. Figure 3-4 and Figure 3-5 show the General Plan Land Use and the Existing Land Use, respectively, for the service area. Table 3-12 shows the land use classifications within the service area and summarizes the vacant and occupied acreage for each land use within the system. Project Number: February 2014

12 Section 3 Land Use Table 3-12 Land Use Classifications and Acreage Total Area (1) Land Use as Vacant Area (1) percent of (Acres) (Acres) Total Occupied Area (1) (Acres) Agricultural 832 5% Commercial 1,279 8% Industrial 156 1% Multi-Family Residential 1,060 6% Open Land 3,565 21% 3,565 0 Parks 119 1% Public 795 5% Single-Family Residential 9,061 54% 3,932 5,129 Total 16, % 8,732 8,136 (1) All Land Use classifications are based on SANBAG General Plan Land Use while vacant acreage was calculated based on Existing Land Use from SANBAG Water Duty Factors After designating land use types for every parcel, the meters with consumption data are overlaid on the parcels to associate consumption with the land use types and the acreage of each parcel. Due to irregularities in digitization, there are locations where meters do not directly overlap with parcels. While these meters are carefully reviewed and some of these meters are attributed to the correct parcel, some of these meters are also omitted from the analysis. Since water duty factors are only calculated for those parcels that have an overlying meter, the omission of a few meters and parcels has negligible impact on the water duty factors. A water duty factor for each land use type is calculated by dividing the three-year average demand for each meter overlying a parcel (from 2010 to 2012) in gallons per day (gpd) by the area (in acres) of the parcel it serves. These values are then averaged for every meter in the system by land use type. Aerial photography is reviewed to ensure that vacant parcels are omitted. Table 3-13 contains the water duty factors for the different land use types based on production. The product of the water duty factor expressed in gpd per acre and the corresponding area of the parcel in acres represents the total demand for EVWD s service area. After applying these factors to the parcels within the service area, the total calculated demand is 27,000 AFY. A review of the consumption data adjusted for water losses indicates that the three-year consumption average for the period is approximately 19,700 AFY. Project Number: February 2014

13 Key to Features Agricultural Multi-Family Residential Public Commercial Open Land Single-Family Residential Industrial Parks Service Area Boundary º Miles General Plan Land Use Document: \\uspas1s01\muni\clients\ East Valley WD\Water System Master Plan \14 Electronic Files - Modeling\GIS\_MXDs\ 2nd try\landusetry2.mxd Date: January 28, 2014 Figure 3-4

14

15 Key to Features Agricultural Multi-Family Residential Public Commercial Open Land Single-Family Residential Industrial Parks Service Area Boundary Vacant/Not Categorized º Miles Document: \\uspas1s01\muni\clients\ East Valley WD\Water System Master Plan \14 Electronic Files - Modeling\GIS\_MXDs\ 2nd try\landusetry2.mxd Date: January 28, 2014 Existing Land Use Figure 3-5

16

17 Land Use Section 3 Table 3-13 Calculated Water Duty Factors Water Duty Factor All Meters (gallons per day per acre) Agricultural 1,600 Commercial 2,050 Industrial 1,000 Multi-Family Residential 3,500 Open Land - Parks 3,250 Public 3,250 Single-Family Residential 3,100 Existing Demand Source: The water duty factors are based on the existing land use. 27,000 AF The discrepancy between the calculated demand and the actual demand for the service area indicates that the estimated water duty factors are not representative of existing conditions. Since single-family residential land use covers over 50 percent of EVWD s service area, refinements to the estimated water duty factor for that land use types is warranted. In order to estimate a water duty factor for single-family residential parcels that is representative of existing conditions, a sampling method is employed. Groups of parcels representing singlefamily houses are selected across 15 different locations spread throughout the EVWD service area. Water duty factors are then estimated for each group. The water duty factor for the residential land use type is considered to be the average water duty factor across all groups sampled. Locations used for sampling are presented on Figure 3-6. Table 3-14 shows the resulting single-family residential water duty factor from the sampling methodology. The adjusted existing system demand due to adjustments in the single family residential water duty factor is 24,700 acre-ft/year, approximately 15 percent higher than existing demands estimated using the population methodology. Table 3-14 Adjusted Water Duty Factor for Single Family Residential Land Use Water Duty Factor based on Sampling Land Use (gallons per day per acre) Adjusted Single-Family Residential 2,700 Total Existing Demand 24,700 Acre-Ft Source: This water duty factor is based on sampling parcels in 15 locations throughout the EVWD service area. Project Number: February 2014

18 Page Intentionally Left Blank

19 Key to Features Service Area Boundary º Miles Document: \\uspas1s01\muni\clients\ Sample Location East Valley WD\Water System Master Plan \14 Electronic Files - Modeling\GIS\_MXDs\ 2nd try\landusetry2.mxd Date: January 28, 2014 Single-Family Residential Sampling Locations Figure 3-6

20

21 Section Build Out Water Demand Projections Land Use Methodology Using the water duty factors described previously in this section, build out water demand projections are estimated based on General Plan Land Use designations obtained from SANBAG. Build out demands for parcels that are currently occupied are estimated using the existing duty factor estimated for the land use types. In order to establish build out demands for vacant parcels that have the potential to develop in the future, an adjusted water duty factor is developed to account for water conservation. Existing water duty factors are lowered by 13 percent to reflect the impacts of conservation. This adjustment is consistent with the 13 percent reduction for future per capita water use discussed earlier in this Section. Table 3-15 shows the water duty factors for existing and future developments. The projected build out water demand is approximately 37,600 acre-ft/year which is 40 percent higher than Scenarios 1 and 2 and approximately 25 percent higher than Scenarios 3 and 4. Land Use Table 3-15 Build Out System Water Duty Factors Existing Infrastructure Water Duty Factors (1) (gallons per day per acre) Future Developments Water Duty Factors (2) (gallons per day per acre) Agricultural 1,600 1,400 Commercial 2,050 1,800 Industrial 1, Multi-Family Residential 3,500 3,050 Open Land - 1,100 Parks 3,250 2,850 Public 3,250 2,850 Single-Family Residential 2,700 2,350 Total Demand (1) Calculated based on land use (2) Accounts for 13% conservation. 3.6 Recommendations 37,600 AF The effects of the on-going recession on future growth cannot be accurately quantified. Although the current slowdown in the economy will affect growth in the EVWD service area in the near future, it is likely that growth will resume and steadily continue within the service area during the 25-year planning horizon of this WSMP. This is also indicated by the resumption in development activity within EVWD s service area with proposed developments such as the Harmony Development, the Arnott Development, the Highland Hills Development, and the Greenspot Village and Marketplace Development being in various stages of planning. In order to be conservative for the purposes of planning, it is recommended the most aggressive growth projection for year 2035 (Scenarios 3 and 4) be utilized for the purposes of sizing infrastructure to serve future growth. Project Number: February 2014

22 Page Intentionally Left Blank