SFPUC Wholesale Customer Water Demand Projections ... - BAWSCA

Purissima Hills Water District Service Area 1
DSS Input Sheet
FINAL INPUT SHEET
Base Year Average Use and Indoor Percentages by Billing Category for DSS Model 2
Old SF Res
Multifamily
Commercial
Industrial
New/Renovated SF Res
Year Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor Average, gpd/a Indoor
2001 716 35% 0 0% 2530 26% 1605 16%
Data for DSS Model - - Base Year 2001
Reconcile agency account billing data and census data
Number of Water Use Water Use,
Total Dwelling Units in Census 2000 for Town of Los Altos Hills
Category Accounts 2001 MGD Use Profile Water Use Indoor Water Use
FY. 2001 3 gpd/a 2 2001 Percent gcd gcd
Old SF Res 1,580 716 1.13 55.58% 188 66
Multifamily 0 0 0.00 0.00%
Service Area Billing Difference between
Commercial 62 2,530 0.16 7.76%
Accounts - Year 2000 billing and census
Industrial 0 0 0.00 0.00%
Single family
2000 Units
No. Buildings
3
data
New/Renovated SF R 465 1,605 0.75 36.67% 1-detached 2,771 2,771
0 0 0 0.00 0.00% 1-attached 32 32
0 0 0 0.00 0.00% Subtotal 2,803 2,803 2,034 -769 Housing Characteristics from U.S. Census Bureau
0 0 0 0.00 0.00% Multi family
Total 2,107 2.04 100.00% 2-units 17 9
Total Water Purchased (produced) 4 = 2.20 MGD 3-4 units 0 0
Unaccounted For Water (UFW) 5 = 5% Percent From 5 year BAWUA Survey average 5 to 9 units 0 0
Estimated UFW for DSS Model = 7.0% Percent 7% if actual is < 7%, otherwise = E25 10-19 units 0 0
Water Produced for use in DSS Model 2.18 MGD Add UFW to Total Water Use 20 or more units 9 9
Assumed a meter for each unit.
Peaking Factor 1.78 Provided by Agency or SFPUC Water Master Plan (or NA) mobile homes 6 6
Assumed a meter for each unit.
Peaking Factor for DSS Model= 1.78 If NA use default value of 1.6. Subtotal 32 24 0 -24
MF Average = 1.36 units/building #DIV/0! units/account
- Blue cells are entered by modeler
- Yellow cells are input to DSS Model Total SF + MF units = 2,835
Data Sources / Notes
NOTES Population and Household Size in Census 2000 for Town of Los Altos Hills Estimated
1. - Communities served (includes all or portions of) the Town of Los Altos and nearby unincorporated areas according to BAWUA survey
Residential
Town of Los Altos Hills Town of Los Altos Hills
Service Area
2 - Average gpd/a is based on a 12-month moving average through December 2001. Indoor use is based on average of 2 lowest consecutive months in the
Census Population Estimated Population Population
winter if meters read bimonthly, or single lowest month if meters read monthly.
3 - Number of accounts is from data provided by water agency for this project (see worksheet with account data in this file)
4 - Total water Purchased (produced) taken from BAWUA for Fiscal Year 2001-2002 or agency if provided.
5 - Unaccounted for Water (UFW) is the percent difference between the total water purchased and the total water use.
6 - For reference see additional population estimates provided in population and employment estimates corresponding to service area table.
7 - Initial estimate based on census data for renter occupied units. For reference see table below that has 2000 census data for corresponding water service
area city or cities. This estimate was revised in order to produce a service area population closer to the BAWUA survey for 2001-2002.
2000 Census Data
Average household size 2.86 Estimate Service Area Dwelling Units for 2001
Average household size of owner-occupied unit 2.88 SF Res 2,045 Equals billing accounts in 2001 from cell C15
Average household size of renter-occupied unit 2.53 MF Res 0 Assume no multi-family dwelling units.
Homeowner vacancy rate (percent) 0.70
Rental vacancy rate (percent) 2.90 Population and Employment Estimates Corresponding to Service Area
Population
Employment
8 -"Old" SF residencial accounts are assumed to use the rate of water use given by 1994 billing records: 716 gpd/account. The number of "old" versus
"new/renovated" residential accounts was determined by assuming a 3% renovation rate since 1994. This assumption corresponds to a "new/renovated"
water usage of 1605 gpd/account in order to maintain the average water use for all residential accounts as given by the billing data for 2001.
Data Sources / Notes
2000 2001 2001 Estimated growth from 2000 to 2001 (CA DOF Projections): 0.61%
Total Population from Census data 6 = 7,902 7950 Estimated employment growth from 2000 to 2001 (ABAG Employment Projections): 0.07%
Subtract Institutionalized Population = 0 0 Water use for the institutionalized population is accounted for in nonresidential billing categories
Residential Population = 7,902 7,950 Residential population shown corresponds to the city or cities represented by Census data
Avg. HHS 7 = 2.79
MF Pop @ MF HHS 7 = 2.86 92 92 0 1.2% Percent of Population that is MF
SF Pop = 7,810 7,858 6,032 98.8% Percent of Population that is SF
SF HHS 7 = 2.95
Total 6,032 100.0%
95 Difference in our estimate and average of 2000-2001 and 2001-2002 BAWUA Surveys
95 Difference in our estimate and the average 2000-2001 and 2001-2002 BAWUA Surveys including institutionalized population
2000 Census data for jurisdiction 7,902 NA
2000 ABAG (jurisdictional) 7,902 2,720
2005 ABAG Projection (jurisdictional) 8,300 2,730
2000 ABAG (subregional) 9,455 2,720
2005 ABAG Projection (subregional) 10,000 2,730
2000 Department of Finance Benchmark 7,902 From State of California Department of Finance (DOF) table E-4 as of 4-1-2000. Website www.dof.ca.gov
Data Prepared : July 24, 2003 By: N. Foged 2001 Department of Finance Estimate 7,950 From State of California Department of Finance table E-4 as of 1-1-2001. Website www.dof.ca.gov
Revised: August 15, 2003 By: J. Hudson 2002 Department of Finance Estimate 8,000 From State of California Department of Finance table E-4 as of 1-1-2002. Website www.dof.ca.gov
FY 2000-2001 BAWUA service area 5,800 NA
FY 2001-2002 BAWUA service area 6,075 NA Service Area Employment is determined by the ratio of the 2000-2001 BAWUA service area population
2001 Employment in Service Area (input to DSS Model) = 420 to the 2000 ABAG Subregional Population and escalated to 2001 using the assumed growth rate (ABAG, 2002).
In order to obtain at least 50 gal/employee/day, this value was multiplied by 0.25.
Definitions / Abbreviations
ABAG Association of Bay Area Governments MF multi family
BAWUA Bay Area Water Users Association MGD million gallons per day
DSS Decision Support System Model No. number
du dwelling unit Pop population
FY Fiscal Year Res residential
gpd/a gallons per day / per account SF single family
gpd gallons per day UFW unaccounted for water
HHS
household size