Two reviewers thoroughly evaluated the manuscript. The main points raised were 1) missing quantitative interpretation of modeling results, 2) restructuring of some sections in the introduction, material & methods and in the results chapter, 3) more specific information about the modeling approach, 4) more specific interpretation about environmental tracer data.

The authors responded to all the raised concerns. It was mentioned that corrections will be implemented into the text. Sometimes, too little information was provided what these new facts in the revised version will be. E.g., the authors have not responded to the question whether evaporation is actual evaporation or not. However, I am convinced that comments like this will be considered in the revised manuscript.

When restructuring the introduction, the authors should keep in mind the very first comment given by the editor, i.e. not stick too much to the case study, but keep it more general because there are lots of things we can learn also for other sites with similar issues.
Second, the authors answered that more information and figures are included into the manuscript. Certainly, the referees were asking for more information and more detailed discussion; however, the manuscript should not be too long in the end. It should be carefully considered to provide some of the Figures or Tables as supplement.

Due to the many comments requiring detailed rewriting of the manuscript, the manuscript will be reconsidered after major revisions have been done.

Dear authors,

It is my pleasure to inform you about the acceptance of your manuscript. Both reviewers, who provided very helpful comments, indicated that all comments were addressed adequately in the revised version.

Thank you for submitting your manuscript to HESS.
Christine Stumpp