Data Analysis Methods For Measuring Impact Of A Conservation-Focused Residential Irrigation Inspection Program
Williams, Chris 1 ; Shimabuku, Morgan 2
1 Center for ReSource Conservation
2 Center for ReSource Conservation
Utilities in the state of Colorado that annually supply more than 2,000 acre-feet of water to their customer base are required by the State of Colorado Water Conservation Board to create and implement water conservation strategies. Residential sprinkler audit programs are commonly used as a tool for Colorado municipalities to achieve their water conservation goals, but little evaluative work has been done to measure the water savings from these efforts (Mayer et al, 2015). This study presents the results from the comparison of four different methods for measuring the amount of water saved at the individual level by participants in Colorado’s largest sprinkler auditing program, Slow the Flow, a program by the Center for ReSource Conservation, offered to residents in 20+ water utility districts across the state. Analysis of water consumption billing records from two years pre- and one year post irrigation audit from over 500 residential households that participated in the program in 2014 were used to answer key questions about irrigation audit impact on water usage as well as to compare the difference between four varying methodologies for calculating water savings and other indicators of watering efficiency on the individual household level. Results show that each method provides a different value of savings for participants with a range between 0 and 19 kgal of mean savings (Fig 1). The median values also ranged from 1-16 kgal of savings. While one method may provide the most statistically and mathematically valid water savings estimations, qualitative evaluation of the different methods reveals that different methods provide unique insight into customer water usage and should therefore be chosen based off of the goals intended of the outcome of the analysis.
Mayer, P., Lander, P., and Glenn, D. 2015. Outdoor Water Use: Abundant Savings, Scarce Research: Journal AWWA, v. 107:2, p. 61-66.