Turf replacement program evaluation
Download as PPTX, PDF0 likes70 views
The turf replacement program by Western Municipal Water District found that on average, participants saved 0.32 AF of water per year. Participants saved an average of 43 gallons of water per square foot of turf removed. For every participant, an average of 2.5 neighbors also replaced their turf. The program was evaluated to have long term water savings and environmental benefits, and helped secure $2 per square foot of supplemental funding for a new turf replacement program.
Turf replacement program evaluation
- 1. Turf Replacement Program Evaluation Melissa Matlock 73rd SWCS International Annual Conference July 29 – August 1, 2018
- 2. Overview • Results • Neighborhood Effect • Discussion • Background • Program Summary • Participants and Controls Image Source: Before and After Image of a Turf Replacement Participant
- 3. Background - CA • In 2014, California experienced record dry conditions • Water supplies dipped to alarming levels • Snowpack in California’s mountains was approximately 20 percent of the normal average for this date • California’s largest water reservoirs had very low water levels for this time of year • California’s major river systems, including the Sacramento and San Joaquin rivers, had significantly reduced surface water flows • Groundwater levels throughout the state dropped significantly Image Source: http://www.drought.ca.gov
- 4. Background - CA • Jan 2014 – Governor declared a Drought State of Emergency • Agencies had to execute a statewide water conservation campaign to make all Californians aware of the drought and encourage personal actions to reduce water usage • Agencies had to implement their local water shortage contingency plans Image Source: www.waterboards.ca.gov
- 5. Background – WMWD • Western Municipal Water District (WMWD) • Located in Southern CA • Serves 23,000 retail customers • Annual average sales of 20 TAF • Water wholesaler to 8 water agencies • Water provided from Colorado River, State Water Project (SWP) from the Northern California Delta River, & local groundwater • SWP ~ 70% Image Source: WMWD GIS
- 6. Background – WMWD • Pioneer Agency • Business model adaptation to balance growth with the needs of the global community • Environmental steward • Diversifying the sources of water for sustainability • As water supplies dwindle, using water efficiently is the lowest cost means to create additional supplies, particularly when compared to developing new infrastructure, drilling additional wells or purchasing water from outside the region. To that end, WMWD provides many rebate and incentive programs to help our customers in partnering with us to work and live efficiently. Image Source: WMWD
- 7. Program Summary Turf Replacement Program • Rebate program to pay customers to rip out their current grass and replace it with climate – appropriate plants • Two Phases • From 2009‒2014, rebate was $.40‒$1/square feet (sqft) • From 2014‒2016, rebate was $2/sqft • Additional funding due to drought emergency declaration • Required 50% plant coverage, design submittal, pre- and post- inspection, mulch • Required to convert irrigation systems to drip, microspray, and/or bubblers • Required receipts, paid rebate up to cost of project or $2/sqft
- 8. Program Summary • 227 Single-family participants • 13% in Murrieta • 87% in Riverside • ~$1.3M rebate dollars invested • Average rebate ~ $6,049 • 792,185 sqft of turf removed • Average sqft ~ 3,458 • Representative of Western Customer Base • Census Block Data Average Customer Base Participants Landscaped Area (sqft) 13,134 13,004 Household Size 4 4 % with College Degree 31% 32% Median Household Income $97,128 $104,142 Median Year Home Built 1994 1995 Water Budget 601 656
- 9. Participants & Controls Participants: • Included in study: 193 • 34 excluded due to data issues • 1 yr pre and 1 yr post Controls - Neighbors: • WMWD customers that did not participate in the Turf Replacement Program but are neighbors to those that did participate • Selected matching lot size, accounting for HOA watering requirements, similar outdoor watering needs (if customer had a pool, then control had a pool), and similar climate and ET factors • Random subset of 52 participants, 100 controls were selected
- 11. Results – Difference in Difference Design Average Water Usage AF/Yr 1 YR Before 1 YR After Controls Participants Assumption 1.53 1.17 1.54 .85 .32
- 12. Results • Participants see an average change of .32 AF of water savings in the year • Controls have no significant change in water usage • Significant difference in usage between the two groups • Followed up in 2016 • Participants saw an average water savings of .39 AF • Water savings continued over time
- 13. Results – Gal/Sqft Hypothesis • Water savings of 31 gallons/sqft of turf replaced Findings • 35 – 43 gallons/sqft replaced • When more sqft was replaced, less water savings • 1000-2000 Sqft “Sweet Spot” • Part of the yard replaced: • 65 – 75 gallons/sqft replaced for front yard • Significantly higher than back yards • Contractor or Customer do the replacement: • Contractor had higher savings, but not significant • Small sample size
- 14. Neighborhood Effect Have the neighbors also switched to drought- tolerant landscape? • 70 customer random subset used in analysis • Analyzed 10 nearest homes Findings: Average of 3.97 neighbors out of 10 had turf replacement (39.7%)
- 15. Multiplier Effect – When did they switch? Significant 1:2.5 Effect – for every 1 participant, an average of 2.5 neighbors also did some sort of turf replacement AFTER the participant • Includes front and back yards from Google Earth Water Use - Measured water usage for the year before and the year after they switched • Average water use reduction was .38 AF/yr/customer • Provides reliability towards water savings estimate
- 16. Discussion WMWD takes transparency seriously and strives to be a good steward of public monies. Every attempt was made to be fair and equitable in this program and to get the most out of every dollar. 1 Year 10 Years Water Savings 61 AF 610 AF Number of Participants 193 193 Rebate Amount $1,371,495 $1,371,495 Cost of Water in Net Present Value (NPV) $22,483/AF $2,248/AF Participants (Western) and Multiplier Effect in NPV 794 customers $1,371,495 Rebate 242 AF $5,667/AF 2,420 AF $566/AF
- 17. Discussion • State of California Executive Order – May 2016 • Make Conservation a Way of Life • Continue to monitor water savings • Determine if savings will last longer than 1-2 years WMWD used results of the program evaluation to support a new Turf Replacement Program
- 18. Summary 3 Important Numbers + Purpose .32 43 2.5 2 AF Average water savings per WMWD customer per year Gals/sqft Average gallons of water saved per square foot of turf removed per year Neighbors Number of neighbors that switched out their turf after the participants did $/sqft The amount of supplemental funding for the new turf replacement program
- 19. www.facebook.com/WesternMWD/@beingwaterwise WMWDVideo1www.instagram.com/westernmwd/ Questions These slides were created to accompany a presentation. They do not include full documentation of sources, data samples, methods, and interpretations. To avoid misinterpretations, please contact: Melissa Matlock mmatlock@wmwd.com