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Summaries of RCT Grants

Evaluation of automated enforcement of outdoor water restrictions in Fresno, California

This is a randomized controlled trial (RCT) designed to help the City of Fresno, California identify the most effective outdoor water restriction enforcement strategy to maximize water conservation while minimizing public complaints.

Grant Recipient: University of Chicago

Term: 2018 –2020

Principal Investigator: Michael Greenstone, Ph.D., Energy and Environment Lab, University of Chicago

Funding: $233,162

Summary: This is a randomized controlled trial (RCT) designed to help the City of Fresno, California identify the most effective outdoor water restriction enforcement strategy to maximize water conservation while minimizing public complaints. Like many water-scarce areas in the United States, Fresno seeks to conserve water by limiting when households can water their lawns, particularly during the hot and dry summer months when drought risk is highest. However, 2016 water meter data indicates that, in a given summer month, over half of Fresno single-family households likely violate these restrictions based on their level of water use.

Historically, Fresno has used a costly system to enforce outdoor water restrictions, under which city employees (“water cops”) visited individual households with recent high water use to visually inspect their lawns for evidence of watering during restricted times, and issued a fine if they found such evidence. However, the city plans to move to a more efficient, automated system to identify and fine violators of water restrictions using data from recently installed smart water meters, which provide near real-time, hourly household water usage data. Because this is a new system, it is unknown what combination of fine threshold (i.e., the amount of water use that would trigger a fine) and fine amount will result in the most water conservation while not being so stringent as to provoke widespread citizen complaints.

This study will randomly assign approximately 100,000 Fresno single-family households with hourly water meters to one of 12 different strategies for promoting water conservation, comprised of various combinations of fine thresholds and fine amounts, or to the existing strategy (i.e., water cops and the existing fine amount).

The study will measure average daily household water use in each of the randomly-assigned groups using data collected by the smart meters during the summers of 2018 and 2019. The City’s Department of Public Utilities will use the study’s findings regarding the optimal fine threshold-level combination to shape its water conservation policies.

The study’s pre-specified analysis plan is linked here.

Grants

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