The revised version of the manuscript (submitted on January 20, 2015) responds to most questions raised by the reviewers. Especially the discussion of results is better structured and more clear and the conclusions are better justified than in the first version of the manuscript. There remain, however, several points requiring more elaboration.

1. The positive correlation between the barometric pressure and groundwater heads is very surprising. More information on the measuring protocols and quality control might convince readers that this effect was not an artefact.

2. I agree with the reviewers that the isotopic data are underutilized. There are also some dubious points in their interpretion.

- What criteria were used to identify bores containing a component of younger water? Only four are mentioned as such (line 420) while in Table 1 one can find four more bores with measurable tritium and not modern radiocarbon levels. In fact, all of these bores contain mixtures of „older” and „younger” groundwaters.

- Groundwater in this study is not „dated” with tritium as no groundwater ages were evaluated. Consider also expressing the tritium results in Tritium Units – this would be more comprehensible for the readers accustomed with the tritium method.

- Fig. 8 shows that the bores can have very different radon levels. According to Fig. 9 bore Euc92 reaches into the granite bedrock which explains high radon content. Does the same apply to Pas95 where radon concentration is even higher? On the contrary, are radon concentrations in Euc90 and Pas96 lower because they are screened in saprolite or alluvium? Finally, higher radon level at the outlet of the eucalypt catchment can be interpreted not as the evidence for groundwater discharge but as a result of radon exhalation from shallow granite bedrock.