We sincerely appreciate your evaluation and the significant suggestions.

The desirable flood management system could be determined by circumstances in the target region such as the topographical characteristics, population trend and its spatial distribution, future flood intensity, and the abilities of maintaining the structures. As the results of this study showed, in the modern era, Japan has adopted a policy of continuous levees to protect flood plains, including rice paddies and farmlands, in order to cope with rapid population growth and food shortages. However, Japan is now in a phase of rapid population and economic decline, and in mountainous areas where continuous levees are not feasible in terms of investment potential and physical capacity, the policy has shifted to protecting only residential areas with ring levees, rejecting the use of continuous levees.

When adopting such flood management systems (including systems that live in harmony with nature), it is important to eliminate obstacles that limit equity participation in the discussion so as not to fall into the ineffective "deficit model" approach (Sullivan et. at., 2024) in the discussion process. And it is necessary to properly evaluate the benefits (cost-effectiveness, including ecological benefits) that flood management systems bring to the region, in coproduction with local communities, and to use the results of such evaluation to build consensus in the community.

Reference:

Sullivan, J. A., H. K. Friedrich, B. Tellman, A. Saunders, and L. Belury (2024), Five key needs for addressing flood injustice, Eos, 105, https://doi.org/10.1029/2024EO240068. Published on 13 February 2024.

We sincerely appreciate your evaluation and suggestions. Below are our responses to your comments. We hope that our responses will satisfy your comments.

(Comment 1)

Regarding data availability:

Can the authors be more explicit in terms of “reasonable request”? Will levee geospatial data be shared? Will the levee length data be fully shareable as it is statistical attributes? Also, please provide the links for other relevant data.

(Response)

Thank you for your question regarding the data availability.

All data, including levee geospatial data, are available. However, some of the photos and data were obtained from the local governments, and their sources (including links) will be listed in the revised manuscript.

(Comment 2)

Figure. 5: which one is the indigenous levee system? Is it Maki Waiyu? The main text does not mention the name and the figure does not highlight the levee, so it is quite confusing. Suggest authors to explicitly mark it on Figure 5, and also revise the texts to be more explicit (for international readers).

(Response)　

Thank you for your appropriate indications.

The red lines in Figure 5 are the indigenous levee system. In the revised manuscript, we will emphasize those lines more and add their text.

(Comment 3)

Figure 3: it would be clearer to directly mention data sources/resolution etc. in figure caption. This is an effective way to more clearly show the info without needing to go back to look for details in methods.

(Response)

We completely agree with your suggestion and will add this figure information in the figure caption of Figure 3.

(Comment 4)

We also found in our study area the ring-type of levees are declining but they remained key in protecting unprecedented floods. They are perhaps the only left memory for a region haven’t flooded for a while and is effective in its protection capability. Could the authors expand on these points?

(Response)

As the case of the Anpachi flood in this paper shows, the ring levees have the ability to reduce flood damages in the event of floods that exceed the capability of the continuous levees. However, in order to achieve this capability, it is necessary to maintain not only the physical/structural capacity of the levees, but also the operational capacity of the levees. In the target area, community flood fighting teams strengthen levees and open/close gates during floods, however as this paper shows, the flood fighting teams in the region are deteriorating. In order for the damage reduction ability of the ring levees to be effective, it is necessary to activate the activities for damage reduction in the local community.