How smart are ‘Water Smart Landscapes’?

Abstract

Understanding the effectiveness of alternative approaches to water conservation is imperative for ensuring the security and reliability of water services for urban residents. We analyze data from one of the longest-running “cash for grass” policies – the Southern Nevada Water Authority's Water Smart Landscapes program – where homeowners are paid to replace grass with desert landscaping. We use a sixteen year long panel dataset of monthly water consumption records for 300,000 homes in Las Vegas, Nevada. We estimate the average water savings per square meter of turf removed with an event study and a panel difference-in-differences approach. We find that participation in this program reduced the average treated home's consumption by 20 percent. We find no evidence that water savings degrade as the landscape ages. Depending on the assumed time horizon of benefits from turf removal, we find that the Water Smart Landscapes program cost the water authority about $1.88 per thousand gallons of water saved, which compares favorably to alternative means of water conservation or supply augmentation.