The manuscript has been reviewed by two experts. Both reviewers find the submitted work to be of interest to HESS readers, provided moderate revisions are made.
The authors have addressed all the major points raised during the review process in their rebuttal. In addition to the reviewers' comments, I encourage the authors to consider the following points:
- Analogy between equations (3) (flow in partially saturated media) and (2) (transport in fully saturated media): While this analogy is clear when the water density is constant, it becomes less straightforward if the density varies in time and/or space. Since this is not crucial for the manuscript, I suggest rewriting equation (2) assuming constant density. Note that equation (4) is written for constant porosity and can be simplified, making the analogy between equations (3) and (4) straightforward.
- Lines 212 - 214. It is unclear why you need to fit a normal distribution to your data, which are clearly not normal. In your response to one reviewer, you state that “preliminary results were similar for different skewed distributions.” Can you use the data directly without fitting a model?
- Table 1. I agree with one reviewer about the need to include more details (perhaps in a supplementary material) about how the optimization procedure was performed. I would also recommend including the uncertainty associated with the optimized values. This additional information is relevant to what is noted in lines 212-214.
- Figure 8. The content of this figure is not clear, as also noted by a reviewer.

Minor:
Line 130 “a balance equation”. Please, specify that it is a mass balance equation.
Line 133 “q” is a vector and should be in bold
Line 143 Please rewrite this sentence, which introduce eq (4). Explicitly state here that Eq. (4) is for transport in fully saturated media (currently this information is only provided at line 153).

The authors effectively addressed the main criticisms identified during the review process, resulting in a strengthened manuscript. Consequently, I recommend its publication.