Residential Water Use

How are we doing?

The city of Tucson has dramatically reduced residential water usage during the past 19 years. In 2010, the city of Tucson had residential water usage rates closer to the U.S. than to the state of Arizona, with 94 gallons per capita per day (GPCD). By 2015, Tucson’s water usage was only 80 GPCD. When compared to the 10 western states, Arizona ranked eighth during 2010 in residential water use. Arizonans used 147 GPCD in 2010, 59 more GPCD than the average for the U.S. All 10 western states used more water per capita each day than the U.S. average. New Mexico used the least, while Idaho the most, at 90 and 168 GPCD, respectively. Currently, the last year of GPCD published data for the U.S. and states is 2010. 

Why is it important?

Water is a finite resource with constant pressure on its availability, especially in the western U.S., where rapid population growth, coupled with a decade-long drought, has placed additional pressure on an already strained resource. Water is used for residential, agricultural, commercial, and industrial purposes, but our focus is on the residential sector. In 2010 the United States Geological Survey reported that an estimated 268 million people relied on public-supply water for their household use.  This represents about 86% of the total U.S. population.   

How do we compare?

When comparing residential water use in the U.S., state of Arizona, and city of Tucson during 2010, Tucson falls in the middle, at 94 gallons per capita per day, which is considerably closer to the U.S. average of 88 than to the state of Arizona, at 147 GPCD. The western states tend to have higher rates of water usage due to their hot and dry climate. 

What are the key trends?

The city of Tucson posted a substantial decrease in residential water use, from a high of 121 gallons per capita per day in 1996, to only 80 in 2015. This is a reduction of 35 GPCD, or 33.9%, over 19 years. The city of Tucson has been proactive in encouraging water conservation by offering a wide range of rebates and incentive programs to residential and commercial customers. Both Arizona and the U.S. reported slight decreases in residential water use between 1985 and 2005. Arizona was down from 145 GPCD in 1985, to 140 GPCD in 2005, a 3.4% decrease. The U.S. experienced a decrease of 5.7% during the same time period. Between 2005 and 2010 the U.S. continued to post a decrease in residential water use with a reduction of 11 GPCD or 11.1%. Arizona did not follow the same trend and posted an increase of 7 GPCD between 2005 and 2010.  

How is it measured?

The U.S. Geological Survey’s (USGS) National Water-Use Information Program compiles and publishes water-use data. The USGS works in cooperation with local, state, and federal environmental agencies to collect water-use information. The USGS compiles these data to produce water-use information aggregated at the county, state, and national levels. The USGS typically reports water usage data for the U.S, states, and counties every five years. Tucson Water provided historic water data for its service area.