Kyusuke Takaki's family has lived in Akizuki, Japan, for more than 200 years. His great-great-great-great-great-grandfather settled there in 1819 — seven generations before him. Today, Takaki, a 10th-generation craftsman, is helping restore the very landscape his ancestors shaped.
In Akizuki, a quiet historic district in the city of Asakura, Fukuoka Prefecture, centuries-old stone channels still guide water through fields and down toward the Notori River below. These channels, built during the Edo period by villagers who redirected mountain-fed streams to irrigate crops and protect their town from floods, are now the focus of an unlikely partnership between local residents and researchers at Kyushu University.
Hironori Hayashi, associate professor at Kyushu University's Faculty of Engineering, grew up visiting the Notori River with his family during every school vacation. "Akizuki and the Notori River were the ideal playgrounds of my childhood," he says. Those childhood memories became the foundation for his life's work.
Hayashi and his colleague Yuichi Kano are restoring abandoned rice fields to functioning wetlands and forests. The project — titled "Community-led nature positive restoration at watershed scale in a biodiversity hotspot of Japan" — improves groundwater recharge and helps reduce the risk of floods and landslides downstream. It's one of only four projects worldwide selected by the National Geographic Society's World Freshwater Initiative, and the only one from Japan.
"The residents sympathized with our approach and offered us their abandoned farmland," Hayashi says. "They are delighted to know that this has caught the attention of National Geographic."
On a recent visit to the Notori River basin, Hayashi crouched at the edge of a pond fed by a redirected stream, adjusting a small sensor buried in the bank. Nearby, Kano reached into the shallows and lifted a cluster of frog eggs between his fingers, turning them gently in the light before lowering them back into the water. The researchers are tracking species like the Japanese toad (Bufo japonicus), looking for signs that the restored environment is thriving.
The stone structures guiding this water are called Ishidatamizeki, a traditional form of river engineering Hayashi has spent nearly 15 years studying and protecting. He was one of the first to recognize the scientific value of these rural landscapes, combining centuries-old local knowledge with modern engineering data.
"The community has been the center of our work here for a long time," Hayashi said, wiping mud from his hands. "We are working together with the people who actually live alongside these channels."
That includes Takaki, whose family once spent 15 years trying to turn part of the land into a tourist destination for iris viewing before the project was abandoned. Now, Takaki watches as younger generations — invited to join fieldwork and nighttime surveys — get their hands dirty learning the science behind toads and river restoration.
The project shows what happens when old wisdom meets new science: ancient waterways get a second life, and a rural community rediscovers the value of the land it never stopped caring for.