As water scarcity intensifies worldwide due to climate change, population growth and economic expansion, a new study offers an unexpected insight: aging populations may significantly reduce future water demand. Research published in Water Resources Research suggests that global water withdrawals could fall by as much as 31 percent by the middle of this century as societies age, potentially easing pressure on rivers, lakes and aquifers.
Water scarcity has emerged as one of the most serious challenges of the 21st century. Climate-driven droughts and floods are becoming more extreme, while freshwater demand continues to rise. Traditionally, projections of water use have focused on population size, economic growth and climate trends. However, this study highlights that population age structure plays a crucial but often overlooked role in shaping water demand.
Study Shows Aging Societies Consume Less Water Across Key Sectors
By analysing water-use data from countries around the world, researchers found a strong statistical link between aging populations and declining water withdrawals. As the share of people aged 65 and above increases, overall water use tends to fall. According to the study, a one percent rise in the elderly population corresponds to an average decline of 2.17 percent in total water use.
The impact is strongest in industrial water consumption, which drops by around 2.6 percent, followed by domestic use at approximately 2.3 percent and irrigation at about 1.9 percent. Older adults generally engage less in water-intensive activities, travel less, and consume fewer goods and services that indirectly drive high water use through industry and agriculture.
The effect is especially pronounced in parts of Asia. Countries such as China, Japan, South Korea and Singapore are projected to see reductions in water use ranging from 42 to 62 percent as their populations continue to age. In contrast, regions with younger populations, including much of sub-Saharan Africa, are unlikely to experience similar declines.
Demographic Shifts Reshape Future Water Planning and Policy
The researchers emphasise that aging does not conserve water directly, but rather reshapes consumption patterns across society. Their models show that demographic aging alone could reduce global water withdrawals by 15 to 31 percent by 2050, compared to scenarios where population age structures remain unchanged.
This finding carries important implications for water planning. Water withdrawals refer to the total volume of water taken from natural sources for agriculture, industry, energy production and household use. Even when much of this water is returned to the environment, rising withdrawals can strain local water systems, particularly in regions already facing scarcity.
While global water demand has historically increased, driven largely by agriculture and industrial growth, aging populations may slow or reverse this trend in some countries. Evidence of this shift is already visible in nations such as the United States, China and Japan, where water demand has stabilised or declined alongside demographic aging.
However, the study also notes that aging does not guarantee reduced water use everywhere. In countries like Russia and the Philippines, older populations remain active in water-intensive farming or rely on inefficient industrial systems, leading to continued or rising water demand. In other regions, economic contraction or migration patterns further complicate the relationship between age and water use.
The researchers argue that incorporating demographic trends into water-demand forecasts could help governments avoid costly overinvestment in infrastructure or, conversely, prevent shortages caused by underestimating future needs. Aging populations may influence decisions around reservoirs, pipelines, treatment plants and conservation policies.
While demographic change may ease water stress in some regions, it does not eliminate the need for strong water management, especially in younger and rapidly growing parts of the world. Climate change, inefficient water use and unequal access remain major challenges. The study ultimately highlights that population aging is not just a social trend but a significant factor shaping the future of global water security.