General appreciation

First of all, I wish to congratulate the authors for their lasting efforts to make available quality-controlled hydrological datasets: publishing an update of their initial dataset is a great initiative, and I hope that it will be an example for the authors of other CAMEL sets. I downloaded the files to check that they behave well, and I understand that the authors already corrected minor issues that were found. The changes between the v1 and v2 are well documented, the authors took the initiative to put as supplementary file a commented version of the first paper, which allows a very quick appraisal of what has changed for somebody who would have already read in detail the initial article (please only remove the comment inside section 3.6.3).To summarize my opinion on this paper and the accompanying dataset I would say: bravo!

Minor comments

1. You provide to precipitation estimates, one from AGCD, the other from SILO. The unexperimented user would have appreciated a recommendation on which to use… and if there are political reasons why you cannot give this advice, please mention it. Also mention the evolution of AWAP to AGCD in Table 1 (the name of the column has changed).
2. I see no mention of karst, though I imagine some of the catchments may be affected. Are there one or two examples that you could provide, just to warn unexperimented en-users that there may be cases where the water balance will be difficult to close?
3. You provide several variables to appreciate the level of anthropogenic influences. Some readers may be willing to analyze catchments that are either “almost natural” or “almost unregulated by reservoirs”. Could you provide a mention on this, and perhaps suggest a threshold on some of the descriptors you provide (i.e. we would consider catchments with impound_fac less than xxx to be almost unregulated).

This manuscript presents an update of the Australian Camels data set. The Camels data sets have become very useful for the modelling community and I greatly appreciate the efforts by the authors. While I am very positive about this publication, I would like to raise a few issues, which might improve the usefulness of this data set.

Major issues:

It might be valuable to provide different options for precip and pot-evap series. However, this also shifts the need to decide on the most suitable data to the user of this data set. So, while I agree that it is a special feature to offer different data variants (as stated on P2L33), I would also say that this is not without problems. It would be good if the authors could provide some guidance on which variants to use as standard. After all, one of the advantages of the Camels data sets is that the user does not have to take this type of decisions and that the modeling community has one common data set. If now each user chosen some different combination of precip and pot-evap then the results of modelling studies will not be comparable after all. So, I would recommend doing some analyses and then recommending which data variants should be used usually.

The same argument can also be made regarding the inclusion of catchments, which have actually been removed for (probably) good reasons in the newer HRS (“let users decide”, P5L106). The authors would be in a much better position to make that decision than most users. Again, I am asking for some clear guidance on when these catchments should (not) be included.

Much of the manuscript is based on McMahon et al. (under review). In the reference list, no information is provided about which journal this manuscript is under review. Honestly, I find it problematic to base a method section on a manuscript that is under review. Until a paper is accepted/available, I would ask the authors to provide more details on the methods and data used for this part of the analysis. Frankly, I was not able to follow/assess this part.

Minor issues:

In the abstract (and elsewhere): Use past tense for your work, “streamflow and climatic information WERE updated” and “information WAS improved”

The use of a reference in the abstract looks rather unusual

P2L36 “this need”, not clear which need this refers to

Table 1: I don’t see what the 3^rd column (reason/motivation) adds and would recommend to remove this column

P4L79: good that the authors clearly state that the selection was done by the ABM, but it would be good to know a bit more (criteria, reference)

Figure 1: show a white and a grey circle in the legend. Now you show a black circle and only mention the colors in text. I found this confusing.

P5L103: unclear what “these 43” refers to

P7L151: is *.mat a suitable format for sharing data?

Figure 3: Please provide some info on the different variables in the figure caption. Finding the variables and information in the tables is rather difficult, so make things easier for your reader (the maps are useful; help your reader understand them!).