texas water development board water conservation best management practices model

Watearth, Inc. Presents:

Texas Water Development BoardWater Conservation

Best Management Practices Model

Input Data

Invite to TWDB Webinar on Model or Questions

• Jennifer J. Walker, P.E., D.WRE, CFMo President, Watearth, Inc.o [email protected] 832.444.0663o www.watearth.com

Project Team• Texas Water Development Board

o John Sutton

• Watearth, Inc. – Primeo Jennifer J. Walker, P.E., D.WRE, CFM

• NewGen Strategies & Solutions, LLC (Formerly J. Stowe & Co.)o Chris Ekrut

• RPS Espeyo Michael Pinckey, P.E.

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10 11 12

Avg.

Mon

thly

Pre

cipi

tatio

n (in

)

Month

Average Monthly Precipitation in Texas CitiesAustinDallas-Ft WorthEl PasoHoustonSan Antonio

0

10

20

30

40

50

60

70

80

1940 1950 1960 1970 1980 1990 2000 2010

Annu

al (i

n)

Month

Annual Houston Precipitation and Evaporation

Precipitation

Evaporation (lakes in full sun)

0

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10 11 12

Med

ian

Mon

thly

(in)

Month

Median Houston Precipitation and Evaporation

Precipitation

Evaporation (lakes in full sun)

Research Project

• Determining Cost Benefit and Demand Savings of Municipal Water Conservation Efforts

Model Assumptions

TWDB Water ConservationBMPs Modeling Tool

• Water Conservation Benefits of BMP Implementation by Customer Class

• 32 BMPs in Model

• Analyze 1 or Multiple BMPs

• Cost-Benefit Analysis

• Avoided Costs for Water/Wastewater Facilities

TWDB Water ConservationBMPs Modeling Tool

• Indoor Fixtures – SF, MF

• Surveys – SF, MF, and ICI

• Outdoor BMPs o Irrigation Nozzles and Controllerso Irrigation Efficiency Evaluationso Landscape Water Budgetso Water Efficient Landscape Design

Instructions

Overview

The INPUT DATA and BMP DATA worksheets are required to obtain water savings and results are computed/reported on the WATER SAVINGS and RESULTS worksheets. Sewer savings are also computed/reported on the SEWER SAVINGS worksheet; however, these results are used only in the optional economics avoided costs calculations. If cost-benefit or avoided cost calculations are desired, the optional ECONOMICS INPUT worksheet must be completed. Results are computed/reported on the COST-BENEFIT and ECONOMICS SUMMARY worksheets. Unless labeled otherwise, all units are in gallons format (gal) or gallons per day (gpd). To facilitate Annual Reporting, results are also reported in gallons per capita per day (gpcd).

Data entry is required in white-shaded cells. Yellow-shaded cells may be revised; however, default data may be used if desired. Read instructions below on individual worksheets before revising cells without white or yellow-shading. Note that other cells are locked for editing and a password is required (TWDB-BMPS). Do not modify formulas contained in these worksheets. Consult the TWDB Water Conservation BMP Model User's Guide for details on required data vs. optional data and additional data sources if local data is not available.

This model does not account for required water efficiency improvements due to plumbing code. This model is focused on utility savings and benefits and does not calculate participant (i.e., customer) costs and benefits.

Year to Denominate Costs (Dollar Year) 2013Base Year to Start Calculations 2013

POPULATION DATA by Year 1990 2000 2010 2020 2030 2040 2050 2060

Historical and Projected Population 1,631,766 1,953,631 2,100,263 2,362,637 2,622,574 2,880,297 3,139,222 3,398,877 Population Growth Rate (%/yr) 1.97% 0.75% 1.25% 1.10% 0.98% 0.90% 0.83%Persons per Household (SF) 2.20Persons per Household (MF) 2.20

Input DataValues in white cells should be entered by the user. Values in yellow cells are default values or reported from other spread sheets in this file. You can change these values, but we strongly suggest that users not change these.

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

1980 1990 2000 2010 2020 2030 2040 2050 2060 2070

Popu

latio

n

Year

Historical and Projected Population

Population

Input Data

• Population and Projections

• Year for Economic Calculations

• User Classes – Amount and # Accounts

• Projected Demands

BMP Data

BMP Data

# of Program Program 1-YearInstallations Start Duration Savings

BMP Name (Items Included in BMP, User Class) per yr yr (yrs) (gpd) Water Savings/Unit

Education and Public Awareness

Education (Educational Outreach, SF) 100 2013 5 95 0.50% gpd/accountEducation (Educational Outreach, MF) 100 2013 5 2,341 0.50% gpd/account

Rebates, Retrofits, & Incentives - Indoor Fixtures

Non-Residential Water Use Surveys (Varies, Industrial) 100 2013 5 113370.5688 1,133.71 gpd/account

Non-Residential Water Use Surveys (Varies, Commercial) 100 2013 5 113370.5688 1,133.71 gpd/account

Non-Residential Water Use Surveys (Varies, Institutional) 100 2013 5 113370.5688 1,133.71 gpd/account

Residential Toilet Replacement Programs (ULFT) (All Toilets in Household Replaced, SF) 100 2013 5 2001.45 12.13 gpcd

Residential Toilet Replacement Programs (ULFT) (All Toilets in Household Replaced, MF) 100 2013 5 2001.45 12.13 gpcd

Residential HE Washer (1 Washer Replacement, SF) 100 2013 5 1277.1 6.45 gpcd

Residential HE Washer (1 Washer Replacement in Unit, MF) 100 2013 5 1277.1 6.45 gpcd

Showerhead and Aerator Retrofit (1 Showerhead and Aerators, SF) 100 2013 5 550 5.50 gpd

Toilet Flapper Retrofit (1 Toilet Flapper Retrofit, SF) 100 2013 5 1280 12.80 gpd

Showerhead and Aerator Retrofit (1 Showerhead and Aerators, MF) 100 2013 5 550 5.50 gpd

Toilet Flapper Retrofit (1 Toilet Flapper Retrofit, MF) 100 2013 5 1,280 12.80 gpd

Rebates, Retrofits, & Incentives - Outdoor

Water Efficient Landscape Design (Turf Grass Replacement, SF) 100 2013 5 770 3.50 gpcd

Conservation Analysis

Residential Water Use Surveys - Showerhead/Aerator Replacements (1 Showerhead and Aerator Replacement, SF) 100 2013 5 550 5.50 gpd/device

Residential Water Use Surveys - Irrigation Audit (Irrigation Audit, SF) 100 2013 5 2600 26.00 gpd/household

Residential Water Use Surveys - Showerhead/Aerator Replacements (1 Showerhead and Aerator Replacement, MF) 100 2013 5 550 5.50 gpd/device

Residential Water Use Surveys - Irrigation Audit (Irrigation Audit, MF) 100 2013 5 20800 208.00 gpd/household

Values in white cells should be entered by the user. Values in yellow cells are default values or reported from other spread sheets in this file. You can change these values, but we strongly suggest that users not change these values.

BMP Data

• # Installations/Year

• Start Year

• Duration of Program

Water Savings

Water Savings

BMP Name 2013 2014 2015 2016 2017 2018 2019 2020

Education (Educational Outreach, SF) 0 95 190 190 190 190 95 0Education (Educational Outreach, MF) 0 2,341 4,683 4,683 4,683 4,683 2,341 0

Subtotal Education & Public Awareness 0 2,436 4,873 4,873 4,873 4,873 2,436 0

Non-Residential Water Use Surveys (Varies, Industrial) 0 113,371 226,741 340,112 453,482 566,853 453,482 340,112Non-Residential Water Use Surveys (Varies, Commercial) 0 113,371 226,741 340,112 453,482 566,853 453,482 340,112Non-Residential Water Use Surveys (Varies, Institutional) 0 113,371 226,741 340,112 453,482 566,853 453,482 340,112Residential Toilet Replacement Programs (ULFT) (All Toilets in Household Replaced, SF) 0 2,001 4,003 6,004 8,006 10,007 10,007 10,007Residential Toilet Replacement Programs (ULFT) (All Toilets in Household Replaced, MF) 0 2,001 4,003 6,004 8,006 10,007 10,007 10,007Residential HE Washer (1 Washer Replacement, SF) 0 1,277 2,554 3,831 5,108 6,386 6,386 6,386Residential HE Washer (1 Washer Replacement in Unit, MF) 0 1,277 2,554 3,831 5,108 6,386 6,386 6,386Showerhead and Aerator Retrofit (1 Showerhead and Aerators, SF) 0 550 1,100 1,650 2,200 2,750 2,750 2,750Toilet Flapper Retrofit (1 Toilet Flapper Retrofit, SF) 0 1,280 2,304 3,123 3,779 4,303 2,418 1,279Showerhead and Aerator Retrofit (1 Showerhead and Aerators, MF) 0 550 1,100 1,650 2,200 2,750 2,750 2,750Toilet Flapper Retrofit (1 Toilet Flapper Retrofit, MF) 0 1,280 2,304 3,123 3,779 4,303 2,418 1,279

Subtotal Rebates, Retrofits, & Incentives - Indoor Fixtures 0 350,329 700,146 1,049,553 1,398,632 1,747,450 1,403,569 1,061,179

Annual Water Savings (gpd)

Education and Public Awareness


Sewer Savings

Sewer Savings

BMP Name 2013 2014 2015 2016 2017 2018 2019 2020

Education (Educational Outreach, SF) 0 47 95 95 95 95 47 0Education (Educational Outreach, MF) 0 1,171 2,341 2,341 2,341 2,341 1,171 0

Subtotal Education & Public Awareness 0 1,218 2,436 2,436 2,436 2,436 1,218 0

Non-Residential Water Use Surveys (Varies, Industrial) 0 86,615 173,230 259,845 346,460 433,076 346,460 259,845Non-Residential Water Use Surveys (Varies, Commercial) 0 86,615 173,230 259,845 346,460 433,076 346,460 259,845Non-Residential Water Use Surveys (Varies, Institutional) 0 86,615 173,230 259,845 346,460 433,076 346,460 259,845Residential Toilet Replacement Programs (ULFT) (All Toilets in Household Replaced, SF) 0 2,001 4,003 6,004 8,006 10,007 10,007 10,007Residential Toilet Replacement Programs (ULFT) (All Toilets in Household Replaced, MF) 0 2,001 4,003 6,004 8,006 10,007 10,007 10,007Residential HE Washer (1 Washer Replacement, SF) 0 1,277 2,554 3,831 5,108 6,386 6,386 6,386Residential HE Washer (1 Washer Replacement in Unit, MF) 0 1,277 2,554 3,831 5,108 6,386 6,386 6,386Showerhead and Aerator Retrofit (1 Showerhead and Aerators, SF) 0 550 1,100 1,650 2,200 2,750 2,750 2,750Toilet Flapper Retrofit (1 Toilet Flapper Retrofit, SF) 0 1,280 2,304 3,123 3,779 4,303 2,418 1,279Showerhead and Aerator Retrofit (1 Showerhead and Aerators, MF) 0 550 1,100 1,650 2,200 2,750 2,750 2,750Toilet Flapper Retrofit (1 Toilet Flapper Retrofit, MF) 0 1,280 2,304 3,123 3,779 4,303 2,418 1,279

Subtotal Rebates, Retrofits, & Incentives - Indoor Fixtures 0 270,062 539,613 808,754 1,077,567 1,346,118 1,082,503 820,380

Annual Sewer Savings (gpd)

Education & Public Awareness


Results

PROJECTED DEMANDS WITH BMPS 2013 2014 2015 2016 2017 2018 2019 2020Total Annual Demands (GPD) 241710000.00 244,729,543.28 247,786,807.99 250,882,265.36 254,016,392.51 257,189,672.52 260,402,595.95 263,655,656.58Peak Demands (GPD) 260240000.00 263,491,027.86 266,782,668.95 270,115,430.63 273,489,826.60 276,906,376.97 280,365,609.91 283,868,057.05Off-Peak Demands (GPD) 223180000.00 227,303,942.15 230,143,518.90 233,018,568.86 235,929,535.18 238,876,866.53 241,861,018.55 244,882,449.86Peak to Average Ratio 1.08 1.08 1.08 1.08 1.08 1.08 1.08 1.08

PROJECTED DEMANDS WITH BMPS 2021 2022 2023 2024 2025 2026 2027 2028Total Annual Demands (GPD) 266,556,393.87 269,489,045.03 272,453,961.18 275,451,496.81 278,482,011.30 281,545,867.48 284,643,432.16 287,775,076.22Peak Demands (GPD) 286,991,170.99 290,148,645.39 293,340,858.29 296,568,191.35 299,831,031.49 303,129,769.36 306,464,799.91 309,836,522.43Off-Peak Demands (GPD) 247,576,644.49 250,300,480.61 253,054,284.34 255,838,384.93 258,653,116.17 261,498,815.05 264,375,822.27 267,284,482.30Peak to Average Ratio 1.08 1.08 1.08 1.08 1.08 1.08 1.08 1.08





Economics

Economics Input

See ASSUMPTIONS worksheet for details on footnoted data sources for default economics values.Item RatesDiscount Rate1 5.48% Current Supply Capacity (MGD) 270.00 Inflation Rates

General2 3.07% Opinion of Year of Incremental Capacity O&M Cost as Electricity 2.00% Priority Project Description Probable Cost Estimate Supplied (MGD) a % of Capital5

Chemicals3 2.33% 1 Water Supply Project No. 1 2,000,000 2013 2.00 1.5%Other Variable O&M 1.50% 2 Water Supply Project No. 2 2,500,000 2013 3.00 1.5%Variable Wholesale Cost 1.75% 3 Water Supply Project No. 3 3,000,000 2013 4.00 1.5%Groundwater Production Cost 2.50% 4 Water Supply Project No. 4 3,500,000 2013 5.00 1.5%Capital Cost4 3.19% 5 Water Supply Project No. 5 4,000,000 2013 6.00 1.5%

6 Water Supply Project No. 6 4,500,000 2013 7.00 1.5%

7 Water Supply Project No. 7 5,000,000 2013 8.00 1.5%VARIABLE COSTS 8 Water Supply Project No. 8 5,500,000 2013 9.00 1.5%

9 Water Supply Project No. 9 6,000,000 2013 10.00 1.5%Wholesale Water Supply (Cost per 1,000 gallons) 10 Water Supply Project No. 10 6,500,000 2013 11.00 1.5%

Fixed 2.00$ Variable 0.50

Total 2.50$

Groundwater Production Fees (per 1,000 gallons) 1.00$

Values in white cells should be entered by the user. Values in yellow cells are default values or reported from other spread sheets in this file. You can change these values, but we strongly suggest that users not change these values .

Economic Calculations• Economic calculations are optional and not

essential to overall model function

• Examples presented herein are samples based on placeholder data and are not reflective of a particular program or experience

• The model’s quantitative results are useful for decision-making, but other non-economic qualitative factors may direct ultimate course of action

Economic Calculations

• Model produces two key metricso Benefit-Cost Ratio (“BCR”)

― Designed to quantify economic efficiency of BMPs

― Assists decision makers in program implementation to achieve the

“biggest bang for your buck”

o Lost Water and Wastewater Revenue― Reduced water use = less revenue

Benefit-Cost Ratio (BCR)• Compares cost of implementation with

benefits of programBCR > 1 = Benefits outweigh cost (Economically Viable Alternative)

BCR < 1 = Costs outweigh benefits (Not Economically Viable)

• BCR value can assist in ranking and making decisions based on economic efficiency

However qualitative benefits may override quantitative results

• Calculated in Real Dollars and Present Value

Benefits Considered

• Avoided Variable Costs― Wholesale Water Supply

(Variable Portion)

― Groundwater Production Fees

― Variable Water Operations and Maintenance (“O&M”)

― Wholesale Wastewater Treatment (Variable Portion)

― Variable Wastewater O&M

• Costs adjusted annually for inflationary impact

Benefits Considered

• Delayed Capital Investment and O&M― Model allows for input of future water supply projects

including cost and capacity

― Using inputs as a baseline, model calculates annual capital and O&M costs with and without Conservation impact

― Calculations are then compared and variances due to delayed investment are considered a benefit of the program

• Model currently only considers benefits in delayed water investment – future updates could consider wastewater investment

Costs Considered

• Cost of BMP Implementation― Direct Labor and Materials

― Indirect Administration and Overhead – Includes Program Marketing and Outreach

― Cost of Customer Rebates

Sample BCR ResultBMP not economically viable, Costs outweigh Benefits

BMP is economically viable, Benefits outweigh Costs

Higher BCR indicates greater economic viability

Lost Revenue Calculations

• Model calculates reduction in water and wastewater volumes

• Annual reductions are then multiplied by the current effective rate for water and wastewater service to determine lost revenueo No adjustment made at this time for future rate increases

• Does not reflect fixed or variable cost reductions at this timeo As cost reductions occur, needed revenue will decrease

o Future updates could consider revenue loss on a net basis

Sample Lost Revenue Calculation

• Program will result in estimated lost revenue of over $37,000

• Utility’s variable costs will be decreased by approximately $12,000

• Rates will need to be increased/fixed costs decreased by $25,000 to account for the utility’s remaining, unrecovered fixed cost

Decision Support / Impact Planning• Primary benefit of economic quantification

is decision support and assessment of program impact

Overall Program is economically viable

Assuming no reduction in current Fixed Costs, revenue impact of conservation is significant

“It’s tough to tell the consumer that ‘Yeah, well, you guys did a great job out there conserving water, but lo and behold, we got hurt financially, so we’ve got to raise your rates,’”

– Jim Dockery, Asst. CM, Wichita Falls – Texas Tribune; February 10, 2014

Instructions• User’s

Guide

• Instructions Page

• Notes in Model

Beta Testing

• Thank-you to Jennifer Nations with the City of College Station and Jessica Woods with the City of Round Rock.

Acknowledgements• Austin Water – Mark Jordan

• College Station – Jennifer Nations

• Dallas Water – Carol Davis and Dr. Nguyen

• El Paso - Anai Padilla

• Fort Worth - Mary Gugliuzza and Micah Reed

• Houston – Carol Haddock, P.E.

• Round Rock – Jessica Woods

• San Antonio Water System (SAWS) – Karen Guz & staff

• San Marcos – Jan Klein

• San Angelo – Toni Fox

Future Improvements

• Improved results as additional research is performed and better data becomes available

• Additional BMPs

• Customer cost-benefit analysis

2 – 8,000 gal.2 – 6,000 gal.

28,000 Gallons

24” Supply Line

greywater

MulchBasins

Flat Bottom – No Island

Island to Prevent Root Rot or For Heavy Clay Soils

Greywater Line

Future Improvements

• It is our hope that statewide use of the model leads to future expansions and improvements to the model by users and the TWDB.

Final Thoughts

• Water Conservation Important Role

• Knowledge of BMP Performance Continues to Evolve

• Integrating Water Conservation + Stormwater Increases Benefits

Invite to TWDB Webinar on Model or Questions

• Jennifer J. Walker, P.E., D.WRE, CFMo President, Watearth, Inc.o [email protected] 832.444.0663o www.watearth.com

texas water development board water conservation best management practices model

Documents

bmp data bmp data

population data

required data

bmp data worksheets

input data population

optional data

default data

input data values