In this Project, I proposed a paddy field infrastructure that utilizes the paddy field function that was in the occupation of Inba-Numa in the age of population decline, declining birthrate, and aging in the future, focusing on the water pollution of Inba-Numa downstream of tone river in the northern part of Chiba Prefecture in recent years, focusing on lake water quality and the problem of the surrounding lowland reclamation paddy field. While co-cultivating rice cultivation and reeds that pass down the culture of "moku harvesting", which are the livelihoods of Inba-Numa with the hands of residents and rice farmers, it will maintain infrastructure functions such as "water purification" and "water storage" of paddy fields that are lost due to abandonment of cultivation. This project will support and protect the lives of Inba-Numa and residents with the power of nature, the power of paddy fields.