1

BMP-Based Target Setting

Presented by DWR at U4 Technical Subcommittee Meeting on

August 25, 2010

2

Baseline and Targets

• Statewide baseline estimated by 20x2020 report– 192 GPCD

• Required target, 80% of baseline– 154 GPCD

• Reduction required by 2020– 38 GPCD

3

Why BMP-Based Targets?

• Takes into account – Prior conservation– Population density and weather– CII intensity– Unaccounted for water

• Savings data available from the 20x2020 study to design the approach and ascertain statewide savings

4

Objectives of the 20x2020 Study

• Assess whether California can achieve a 20% reduction in per-capita use by 2020

• Identify the mix of measures and approaches required to reach above goal

• The study goes beyond BMPs to identify potential sources of savings

5

Sources of Savings in the 20x2020 Study

• Water Use Efficiency Comprehensive Evaluation (WUECE) used to develop savings estimates

• Savings under Basic Measures capture– plumbing codes, cost-effective and grant funded BMPs, their

interactive effect, plus ET controllers• Savings under Additional Measures capture

– Impact of exceeding BMP coverage goals– Lower levels of unaccounted for water– Irrigation restrictions– Recycling and CII PBMPs

6

Table 7 From 20x2020 Report

Savings From Basic Measures  

Code 8

80% of local CE 11

Grant funded 4

Efficient clotheswashers 3

Residential ET controllers 3

TOTAL (basic measures) 28

Savings From Additional Measures  

Accelerated coverage goals 9

Recycling 3

Water loss control (40 g/conn./day) 6

Irrigation restrictions (2 days/week) 16

Miscellaneous PBMPs 2

TOTAL (additional measures) 37

7

Our Approach to the Problem

• Identify BMPs that are easily quantifiable– or simplify the quantification method relative to

what was used in the WUECE• Assess whether selected BMPs achieve the

20% savings goal by 2020– If not, evaluate the impact of Additional Measures

• Develop an overall scaling factor to ensure state reaches its mandated goal

8

Exploratory Analyses Suggest…

• Models and data exist to quantify the impact of most BMPs– CII savings will be quantified as 10% of baseline CII

GPCD. WUECE’s methods were more complex• Increasing coverage goals in some instances is

desirable– It raises savings, preserves equity, and simplifies

the calculation methodology

9

Components of the Savings Calculation

• BMP 1.2 Water Loss Control– Savings shall be calculated on the basis of reaching a loss

goal <=40 gals/conn/day (from Additional Measures in the 20x2020 report)

• BMP 1.3 Metering– Assume all urban connections are metered prior to 2020:

savings 20% of pre-metered use• BMP 3.1 Residential Assistance Program

– Estimate savings potential without including LF showerheads in the calculation: 8.8-21 gpd (mf/sf) at 15% decay

10

Components of the Savings Calculation

• BMP 3.2 Residential Landscape Surveys– Evaluate savings potential per the MOU: 15%

savings at 10% annual decay• BMP 3.3 High Efficiency Clothes Washers

– 14.4 gpd savings; washer life 14 years; 10% freeridership

• BMP 3.4 WSS toilets– Savings depends on toilet type, program type, and

location: see BMP database document

11

Components of the Savings Calculation

• BMP 4 Commercial, Institutional, Industrial– Estimate savings as 10% of baseline CII GPCD

• BMP 5.1 Water budgets for dedicated irrigation– Evaluate savings potential per the MOU: 19%

savings at 10% annual decay• BMP 5.2 Landscape surveys for mixed use CII

accounts– Captured in BMP 4

12

Components of the Savings Calculation

• For WSS, CII urinals, LF showerheads and HE clothes washers calculate savings potential based on assumed 2020 saturation goals – Saturation of 3.5 (or greater) g.p.f. toilets <= 5% by

2020– Saturation of non-efficient CII urinals <= 5%– Saturation of non-LF showerheads <= 5%– Saturation of (WF=6) HE clothes washers >= 85%

13

Model and Data Requirements

• Models to estimate saturation rate of residential and CII WSS, LF showerheads, urinals and HE clothes washers at midpoint of baseline already exist– These models factor in the effect of plumbing

codes and past active programs– Unit savings assumptions from the MOU

• Data and methods already exist in the MOU for evaluating the remaining BMPs

14

How Does the Approach Work Statewide

• The 20x2020 models suggest that our calculation approach reduces 2020 usage by 36 GPCD– This is after including a correction for the

simplified CII savings methodology we are proposing relative to the WUECE

• The target derived from the proposed calculations would be further lowered by 2 GPCD to ensure state reaches its goal