Voices Reconnecting the Water Veins Water Resource Fluctuations and Choices for the Future 2020s

Voices Reconnecting the Water Veins Water Resource Fluctuations and Choices for the Future 2020s

Securing water used to be taken for granted. However, with the combination of climate change and aging infrastructure, this assumption itself is quietly crumbling. Rainfall patterns are being disrupted, heavy rains and droughts are alternating in the same watershed, and there are concerns that the number of times and days that dams are depleted will increase. In Japan, in addition to the lessons learned from the Fukuoka drought and the drought in the archipelago, it is predicted that the number of rainfall-free days will increase due to climate change in the future, further increasing the risk of drought.

On the other hand, many of the water pipes, dams, and water purification plants that are the blood vessels that carry water were constructed during the period of rapid economic growth, and the number of pipelines that have exceeded their legal service life of 40 years continues to increase across Japan. The renewal rate is less than 1 percent, and some estimate that at this rate it will take more than 100 years to renew all of them. Aging pipelines increase the risk of water leakage, road subsidence, and water cutoffs during earthquakes, creating a structure in which "water that should have been secured" is lost along the way.

Under these circumstances, what is required is not just temporary water withdrawal restrictions every time there is a drought. It is important to increase the effective amount of water through leakage prevention measures and to change the "use of water itself" through demand management. The Ministry of Land, Infrastructure, Transport, and Tourism's Water Resources Policy and "Current Status of Water Resources in Japan" propose a "risk management" water resources policy that simultaneously addresses a variety of risks, including the emergence of drought risk, the severity of water-related disasters, aging of water infrastructure, and fluctuations in water demand due to changes in industrial structure.

One of the keys to this is wide-area cooperation among municipalities. Small-scale water utilities alone cannot keep up with aging water systems due to insufficient renewal costs and human resources. A system in which facilities and pipelines are systematically renewed in a wide area and mutually accommodate each other in the event of a disaster is the foundation for supporting water security. At the same time, the concept of "basin-wide integrated water management," in which stakeholders work together throughout the entire basin, is also attracting attention. This is a framework that considers water source forests, agricultural water, and urban water supply as an integrated system, and aims for management and consensus building from upstream to downstream.

Another pillar of this framework is the citizen-participatory review of water conservation and use. The "Water Saving Citizen's Movement" and "Wakuwaku Water Saving Club" in Kumamoto City, as well as water saving months in various regions, continue to share ideas for saving water at home and conduct social experiments to "visualize" the water consumption of the participants. The spread of water-saving devices through subsidized programs, water-saving theme songs, and stickers may seem modest at first glance, but they are an attempt to make people realize the value of water in a way that is close to their daily lives.

In an age when it is becoming increasingly difficult to secure water, the question is not only "where to get water and how much to get. The question is not only "how much water to take from where," but also "how much water to deliver without waste," "how to share," and "how much to return to nature. The phrase "reconnecting the water network" is not only referring to the pipes and water sources lying underground, but also to reconnecting the relationships between people and people, and between people and watersheds. The choices we make regarding water are becoming a mirror that reflects the shape of the region itself in the future.