Dear Authors,
I am happy to see that the referees gave very positive feedback concerning your manuscript.
Please revise your manuscript according to their suggestions.
I saw that referee#1 made the following suggestion: "One thing I might suggest is
a diagram or table depicting the different sampling plots/transects and how many/what
kind of samples were taken in each. This is not completely necessary, but with such a wide variety of variables being examined, it might be helpful." You did not reply to this suggestion, but please consider it during your revision.
Best regards,
Theresa Blume

Dear Authors,
thank you for providing your revised document. I think we are almost there, but I would like to see a few more improvements and a follow up on some of the reviewers' comments:
Please respond to the suggestion by referee #1 (and myself): a diagram or table depicting the different sampling plots/transects and how many/what kind of samples were taken in each. This could mean taking table S5 from the supplement and extending it to provide a bit more information on sampling (also of water sources etc.).
Figure 2: do you also have stable water isotope data from the stream/river? Why do you assume that the stream water during flooding has the stable isotope signature of groundwater? Depending on the runoff generation process, flood water could also include a higher proportion of rain water.
Figure 3: please also show E. camaldulensis and C. opaca in different colors. Labels a,b,c,d are in different fonts and different locations (c is overlapping with the box of the plot)
Figure 6 and 7: please also show E. camaldulensis and C. opaca (panel b) in different colors
p.31 l.1 “Finally, rates of water use and changes in midday water potential between the end of the wet-season and the end of the dry-season were minimal for E. camaldulensis and C. opaca…” – Do you mean “differences in rates of water use”?
p.31 l.12 it would be easier for hydrologists to follow if you replace Mulga with A. aneura here and then use that name consistently.
The new map shown in your response is not included in the revised supplementary material. What are numbers 1-4 on this map? This should be explained in the caption. Caption is missing.
Does vertical distance mean elevation above the stream? Maybe rephrase, vertical distance seems a bit awkward.
There seems to be a contradiction between results and conclusions, please correct this:
Conclusions: “as distance increased from a creek near a flood-out associated with aquifer recharge, foliar Δ 13C increased and WUEi decreased for E. camaldulensis and C. opaca, but not for A. aneura”
Results: “For the two deep-rooted species, a significant decline in Δ13C (and hence an increase in WUEi) was observed with increasing distance from the creek (Fig. 6a, b).”
Please read through your manuscript again and check for readability and errors.

Best regards,
Theresa Blume

Dear Authors,
thank you for your revisions. Your manuscript can be published after technical corrections (please see comments directly in both the manuscript and the supplement).
Best regards,
Theresa Blume