In the previous article, I explained that water is the foundation of civilization and that marine civilization is a new form of civilization built on the “water cycle.” So, how have we utilized water up until now？ Modern civilization has developed by “carrying” water to where it is needed. And now, that very system is facing a major turning point.

■A Society Built by a “Water-Carrying Civilization”

In modern society, systems are in place to secure water from dams and water treatment plants, supply it to cities and communities through long water mains, and then drain and treat it via sewer systems after use. This water and sewer system has provided a stable supply of safe water, supporting people’s daily lives and industrial activities. It is truly a vital piece of social infrastructure that underpins modern civilization.

However, many of these systems were designed based on the premise of a one-way flow: “drawing in large volumes of water, supplying large volumes of water, and discharging large volumes of water.” In the society of the past, this system was considered the most rational approach.

■A Changing Era, New Challenges

However, the social environment is undergoing significant changes. While water shortages and droughts are becoming more severe around the world, extreme weather events such as torrential rains and floods are also on the rise. Furthermore, due to population decline and aging infrastructure, the burden of maintaining water supply and sewer systems is growing year by year. Moreover, when large-scale disasters strike, it is not uncommon for water and sewer systems to fail, causing the entire region to lose its basic functions.

What is needed in the coming era is not a system to transport water over long distances, but rather a system that enables each region to utilize water sustainably.

■The Concept of Water as a “Circulating Civilization”

In the civilization of the future, it will be crucial to adopt a mindset that does not treat water as a one-time resource, but rather purifies, reuses, and recirculates it within the local community. This is not merely about conserving water; it is about building a system in which communities themselves nurture, protect, and continue to make the most of water.

By placing the water cycle at the center, we can efficiently utilize energy, food, and resources within the community, leading to a sustainable society in harmony with nature.

From a civilization centered on “transportation” to one centered on “circulation”—that is where the possibilities of a new era lie.

■The New Water Infrastructure Envisioned by Seatopia

Project Seatopia will put this concept to the test in the real world. First, on board the ship, to make the most of limited water resources, we will establish a system that recycles water— purifying and reusing it on board rather than discarding it after a single use. Domestic wastewater will be treated using advanced purification equipment and reused for various purposes. Furthermore, by combining rainwater harvesting with seawater desalination technology, we will secure new water sources while enabling the sustainable use of limited water resources.

In addition, by managing water usage in real time through sensors and AI to optimize water quality and consumption, we will achieve efficient water management that supplies exactly the right amount to exactly where it is needed.

In this way, by transforming the ship itself into a “small water-cycling society,” we build a self- sufficient living infrastructure while minimizing dependence on external infrastructure.

This water-cycling system, proven aboard the ship, aims to be deployed in the future to remote islands, coastal regions, and even as emergency support bases during disasters, serving as a basic model for a water-cycling civilization.

Furthermore, by building a network of “decentralized water infrastructure” in which each region is self-sufficient while supporting one another, we aim to create a society that is resilient during disasters and sustainable in peacetime.

Seatopia is a platform for marine civilization that demonstrates this new water infrastructure.

■Civilization: From “Carrying” to “Circulating”

Civilizations to date have developed by transporting water to where it is needed. The civilization of the future is an era in which water will circulate within local communities, building a society where people and nature can coexist sustainably.

A marine civilization is not merely a civilization that utilizes the ocean. It is a new form of civilization that incorporates the water cycle into the fabric of society, thereby realizing regional self-reliance and mutual aid.

From a “civilization that transports water” to a “civilization that recycles water.”

This transition will surely mark a new step forward in supporting the society of the future.