Low-Flow Appliances and Household Water Demand: An Evaluation of Demand-Side Management Policy in Albuquerque, NM

Residential rebate programs for low-flow water devices have become

increasingly popular as a means of reducing urban water demand. Although program

specifics vary, low-flow rebates are available in most U.S. metropolitan areas, as

well as in many smaller municipalities. Despite their popularity, few statistical

analyses have been conducted regarding the effects of low-flow rebates on household

water use. In this paper, we consider rebates from the Albuquerque Bernalillo County

Water Utility Authority (ABCWUA). Using panel regression techniques and a database

of rebate recipients, we estimate the marginal effects of various low-flow devices

on household water demand. Results indicate a negative correlation between household

water use and the presence of most low-flow devices, after controlling for water

price and weather conditions. Low-flow toilets have the greatest impact on water

use, while low-flow washing machines, dishwashers, hot water recirculators,

showerheads, and xeriscape have smaller but still significant effects. In contrast,

air conditioning systems and rain barrels have no significant impact on water use.

In addition, we test for possible rebound effects (i.e. whether low-flow appliances

become less-effective over time due to poor rates of retention or behavioral

changes) and compare the cost effectiveness of each rebate using levelised-costs. We

find no evidence of rebound effects and substantial variation in levelised-costs.

The latter result suggests that water providers can improve the efficiency of rebate

programs by targeting devices that offer the greatest benefit per rebate

dollar.