Why Overall Water Use Is Declining in US Despite Population Growth

Water use efficiency was a hot topic among sustainability experts in 2018, as changing weather patterns, a US population increase of 4%, and aging water infrastructure continue to put a strain on our nation’s water supply.

But for all the dire news about the negative impacts of climate change on weather patterns, water restrictions and storms that spilled wastewater into city streets, good news happened, as well.

Cities and municipalities are moving forward with innovative water conservation efforts. El Paso, Texas, for example, is building an advanced purification system that will treat sewage water and turn it directly into drinking water. Unlike other potable reuse facilities in the US, which return drinking water to a treatment plant or blend with other raw water sources, the facility will use a direct-to-distribution approach, with the purified water flowing directly into the drinking water distribution system, according to the city.

In the fall, New York City’s Department of Environmental Protection (DEP) launched a Water Challenge to Universities. It was the fourth of New York City’s sector-specific challenges and builds off the success of previous challenges to hotels, restaurants, and hospitals. As part of the challenge, the six participating universities will work to reduce their campus-wide average water consumption by 5%, which would be a savings of approximately 1.3 million gallons of water per month.

California’s water managers have continued to look for creative strategies for managing their water portfolios, including the development of localized sources.

And in Arizona, a consensus is emerging for approving a drought contingency plan that would save water in Lake Mead and allocate shortages of Colorado River water within the state, writes AZCentral.com. In fact, 2018 may have been a turning point for Arizona in terms of water management, according to the article.

Large companies have also continued to focus on water management strategies. Lowe’s is using irrigation technology to reduce water use for store landscaping and is saving about 650 million gallons of water per year, for a total annual reduction in water costs of about $5 million across more than 900 stores.

Target and Archer Daniels Midland both committed to improving their water stewardship. And KB Home said it has built an “industry-record number” of WaterSense labeled and Water Smart-certified homes, estimating that those homes conserve 1.4 billion gallons of water annually.

Similar efforts in the last decade have contributed to a significant drop in US water use which, in 2015, was at its lowest level in 45 years, according to the most recent study from the US Geological Survey (USGS).

The USGS conducts a study on water use throughout the US every five years. The 2015 study showed that US water use was 322 billion gallons per day (bgd), down 9% from the 354 bgd that was shown in the 2010 study.

Water withdrawal in the US grew every five years from 1950 through 1980, when it hit a peak of 430 bgd. Following a slight decline in 1985, withdrawal levels remained relatively constant through 2005, when they began to drop.

Thermoelectric power generation, irrigation, and public supply make up 90% of water use in the country. Of all categories of water use, thermoelectric power use decreased the most, down 18% from 2010.

Since 1985, industrial water use has consistently declined and 2015 estimates are about 43% less than in 1985.

As it did in the period between 2005 and 2010, withdrawals for public supply declined between 2010 and 2015, despite a 4% increase in the nation’s total population, USGS says. The number of people served by public-supply systems continued to increase and the public-supply domestic per capita use declined to 82 gallons per day in 2015 from 88 gallons per day in 2010.

The USGS is the world’s largest provider of water data and the premier water research agency in the federal government.