Thank you for your well-considered and detailed comments – these will certainly improve the communication of our work and the quality of the article overall. Replying to each comment in-turn:

1. Clarify the Framing Around Data Scarcity

We agree this can be framed more clearly. We intend to communicate that the issue of scarcity relates in most cases to locally-collected, in-situ or high resolution hydrological datasets and will add that clarification. And indeed for existing datasets (such as remotely-sensed data), issues of data access, sharing and use remain barriers despite greater availability. We will make this clearer in the introduction.

1. Relate More Clearly to Existing Research Infrastructures

We agree that the article will benefit from this. We will add to the introduction to provide reader context on how FDRI fits in with broader research infrastructures and observatories. Then (relating to your Comment 6), we will offer more reflection in the discussion on the implications of FDRI’s design recommendations for its future role and relationships with other infrastructures (in sub-section ‘Considerations for Operational Sustainability’). We especially agree that there is a need to relate to those that have broader ecological/environmental focuses such as eLTER in these sections, as the systematic review procedure maintained a narrower focus on hydrological research and data infrastructures.

1. Improve Transparency and Justification of Stakeholder Sampling

We will expand the explanation in Section 2.2 to provide clearer details about respondent selection, including roles, sectors, and levels of seniority. We will also add detail of how preliminary workshops guided the selection of key informants through purposive and snowball sampling of FDRI’s major expected user groups. Through FDRI’s large project network, we were able to purposively sample key informants from expected major user groups, whilst specifically targeting individuals recognised by others to be knowledgeable about data and research infrastructures like FDRI. Sampling participants with prior experience and understanding of such infrastructures enabled deeper reflections on design elements and priorities.

We emphasise for transparency in the methods that the sample size (n=20) was intended for breadth and depth in a formative design phase and that further rounds of stakeholder engagement are planned. On reflection, we can better clarify this in the conclusion (such as after Line 587) to ensure the reader is aware of sample size limitations and will add this to the revised manuscript.

1. Refine Terminology and Conceptual Framing

Thank you for this observation. The terms used, such as those you highlight, reflect the language commonly used by our interviewees, and we chose to retain them to stay closer to the original expressions of stakeholder perspectives. Also, where they are used, these terms are supported by more specific sub-themes in the tables and are discussed in more detail throughout the text. We hope this helps clarify their meaning. That said, we will keep this point in mind when reviewing the full manuscript in light of all reviewer feedback and consider whether any further clarification or rewording could be helpful to the reader.

1. Clarify the Manuscript Structure: Results vs. Discussion

Thank you for this thoughtful comment. We agree this raises an important point about what constitutes “results” in interpretative qualitative research, and we could improve the article by adding clarifications/modifications to the manuscript.

Firstly, to address the comment on normative claims, we agree there are occasions when interviewee perspectives on FDRI are combined with literature references, then language is used that presents interviewee perspectives more normatively (such as Line 269). We will revise phrasing throughout the results to make it clear when stakeholder recommendations made are specific to FDRI. Then, where there is broader support from the literature, that will be noted additionally. This should help distinguish FDRI-specific observations from generalised recommendations in the results.

Secondly, regarding restructuring, we recognise that Section 3.3 of the results in particular seems more interpretive than descriptive, as the priorities presented are interpretative syntheses based on themes that emerged across the full interview set - not from a single question as in Sections 3.1 and 3.2. We believe this section still belongs in the results. It is common when conducting interviews and inductive analysis for ‘emergent’ points of emphasis (or themes) such as these to arise that span across different questions. In more structured approaches to qualitative research these might be omitted from the results. Here we feel that, pragmatically, and given the semi-structured nature of these interviews, the level of emphasis and evidence supporting these structural design priorities warrants their reporting as an important, relevant result from the semi-structured interview and literature review procedure.

We will address this second point explicitly with more explanation in the final paragraph of the methods. Specifically, this will justify the inclusion of Section 3.3 in the results section and explain how ‘design priorities’ had a dedicated round of thematic coding inclusive of all questions, in contrast to Sections 3.1 and 3.2, where only direct responses to single questions were coded. We will also add clearer explanation at the start of Section 3.3 in the results (Line 390 onward) about how these design priorities were recorded separately in the interview analysis.

1. Strengthen the Discussion and Critical Reflection

This is a very helpful recommendation and links back to Comment 1. We will add a new paragraph in the discussion Section ‘Considerations for Operational Sustainability’ about implications of this study’s findings for FDRI’s (and equivalent infrastructures’) future role and relationships with other research and data infrastructures, drawing on the references that will have been newly introduced to the introduction.

Best wishes from the Authors.