The paper entitled 'Water flow timing, quantity, and sources in a fractured high mountain permafrost rock wall' by Ben-Asher et al. presents the results of a two-year campaign monitoring fracture water in high elevation permafrost at the Aiguille du Midi, France. The subject is currently of great interest, as rock slope failures in high mountain areas appear to be linked to the loss of sealing permafrost ice plugs in rock fractures and to deep-seated infiltration of water into the newly accessible fracture systems. The extent of the fracture systems and their hydrology is poorly known. This study uses a combination of methods to identify the sources of water flowing through rock fractures, the rates and timing of flow, preferential flowpaths, and the thermal regimes of the rock and water. Most of the relevant literature is cited (see my suggestions in the detailed comments (attached) for further literature), but in some cases the references do not appear (error message). Most of the figures need enlarging and labelling to improve their legibility. The figure captions do not adequately describe the figures. The language is mostly clear but with some grammatical or consistency issues (see detailed comments). Some small changes to the paper structure should be considered, particularly in sections 4.3.1 and 4.4, where the explanations/hypotheses should be moved to the Discussion. The paper is highly relevant and I suggest it be accepted for publication, with major modifications.

The paper by Ben-Asher et al. investigates the flow dynamics and surface-subsurface connectivity in a fractured domain located in a steep permafrost-affected high-altitude system in the Aguille du Midi site (Mont Blanc Massif). The Authors present a rare and intersting dataset resulting from a two-year set of temporally resolved measurements of flow rate, temperature, electrical conductivity, tracer fluorescence, and isotope analyses. These data, along with meteorological data, are then analyzed to infer the amount of surface water infiltrating through permafrost-affected rock walls.

I think the work would benefit from a set of revisions which range between major, moderate and minor, as detailed in the attachment.

The manuscript by Ben-Asher et al. presents a detailed investigation of water flow dynamics within a fractured permafrost rock wall at the Aiguille du Midi, Mont Blanc Massif. Using a multi-method approach, the authors examine the sources and timing of water flow in a high alpine permafrost environment. The methodology is innovative within the context of permafrost research, and the dataset is both rare and valuable. The study makes a meaningful contribution to our understanding of water infiltration processes in permafrost-affected bedrock.

However, several aspects of the manuscript require significant improvement before it can be considered for publication.

First, many of the results are not adequately supported by graphical representation or statistical analysis. Key claims are made without sufficient visual or quantitative evidence, leaving the reader unable to verify the conclusions (e.g., Tables 2, S1, S2, S3). Additionally, several numerical values lack precision and are often presented without measures of variability (such as standard deviation or coefficient of variation), despite the fact that the processes under study are known to exhibit high variability.

Second, the graphical presentation of results is limited and in need of substantial improvement. Overall, the figures do not sufficiently support the analysis and should be revised for clarity and readability. For example, Figure 5 and 7 both show water flow and air temperature, but in neither case are the values clearly legible or effectively presented.

The text also requires revision. The introduction is overly general and lacks site-specific details—such as fracture characteristics or distances between loggers and snow cover—that are critical to contextualizing the study. Sections 4.1.3 and 4.1.4 are particularly difficult to follow and include figures that do not appear directly relevant. Furthermore, the separation between results and discussion is not always maintained; some interpretive content appears in the results section, while parts of the discussion are descriptive rather than analytical. The discussion would also benefit from comparisons with similar studies to better situate the findings within the existing literature.

Although the manuscript is mostly well-written, it would benefit from a thorough proofreading to address grammatical, stylistic, and consistency issues.

In summary, this paper presents a unique and promising dataset with strong potential to advance the field, but requires major revisions in terms of structure, data presentation, and clarity, as listed in the attached file. I recommend the manuscript be accepted pending major revisions.