Implications of Declining Water Use
WRF RESEARCH, AS well research from other sources, has definitively demonstrated that residential end use is declining and will most likely continue to decline. The primary reason for
this decline is the installation of water-efficient appliances throughout the home. The decline
in water use across the residential sector, even as populations increase, poses a diverse set of
challenges as well as opportunities.
As drinking water utilities sell less water, their revenues decrease, which can make it difficult
to cover operating expenses as well as upgrade deteriorating infrastructure. Utilities may be
forced to cut costs, raise rates, or both. Even wastewater systems can be adversely affected by
declining water use. With residential customers installing more efficient fixtures and cutting
down on household water use, the reduced water flows from homes are unable to push waste
through wastewater collection systems effectively. When solid waste sits too long in the pipe, it results in unpleasant odors, and
can even corrode wastewater pipes prematurely.
The expanded use of water-efficient appliances, as well as conservation in general, has some obvious benefits. Regions without
abundant water sources, such as the American Southwest, depend on conservation to meet supply needs. Climate change and
drought can create substantial stress on water supplies, requiring strong conservation programs.
To help the water community and the public better understand recent trends in household water use, the Water Research
Foundation is pleased to announce the publication of Residential End Uses of Water, Version 2 (project #4309). This expansive project
provides an update to WRF’s original 1999 residential end use study. The new study includes data from 23 participating utilities across
the United States and Canada, and presents detailed information and data about how residential water use has changed since 1999.
The 2016 study includes some notable additions and amplifications over the 1999 study, including more varied site locations,
collection of hot water end use data, more detailed landscape analysis, and expanded water rates analysis. Overall trends and
findings of the #4309 study are summarized in the feature article of this issue of AWR. A high-level summary can be found in the
Executive Report (#4309A), which is available on the WRF website. The full report (#4309B) is also posted on the WRF website. Lastly,
the project produced a database that contains all of the end use water events recorded during the 2016 study, along with the survey
response data, historic billing data, other data obtained for each study site, and summary data from other studies.
The decline in residential end use is truly a double-edged sword. Overall, society benefits from water conservation. But many
water utility costs are fixed regardless of water use. And that doesn’t include the gaping hole in funding for upgrading infrastructure.
The Water Research Foundation has numerous completed and ongoing projects to help water and wastewater utilities with rate
setting, cost reduction, management strategies, and infrastructure renewal. Together, we’re focused on building and maintaining
a sustainable water sector.
Chair, Board of Trustees
Robert C. Renner, PE, BCEE