The manuscript is a modeling study assessing the spatial generation of surface runoff in the Ganges basin. However, the actual model has already been published, and so I do not see the paper as having adequate technical content to be published as a stand alone paper in HESS. I have two possible suggestions for the author:
1. There are suggestions made by reviewer 3 that if adequately addressed can be sufficient to warrant publication. For example, consideration of upstream-downstream flows, or addressing the question of subsurface storage and its impact on the timing of the flows.
2. The other option would be to integrate this paper with the other paper in HESS instead of a two paper series.
I would ask the authors to consider either or both these options for publication.

Dear Authors:
I read through all the reviewer comments and responses. I agree with the reviewer 3 that the paper still lacks a clear discussion section that brings it all together, and highlights the contribution of the paper. Please address the comments of reviewer's 1 and 3.

Dear Authors:

You provided a point by point responses to all reviewers, except for Reviewer 1. I think the points raised by Rev 1 are important and needs to be addressed. Although I have said reconsider after major revisions, I will send it out for review only if I absolutely need to. A detailed response to the following questions would help me do a quick turn around of the manuscript.

For example, Rev 1 states

"There are still serious problems with the additional analysis, and problems with the hydrological definitions and interpretations. The simulation of the impact of the two scenarios to meet unmet demand (Figure 5) don't seem to actually meet that demand by increasing ET, and therefore underestimate (or rather don't even account for) the impact of meeting unmet demand on streamflow; rather, they only account for the impact of reallocating direct runoff to GW and baseflow. Specifically, either the methods or the simulation results in figure 5 are incomplete. Results in figure 5 are said to represent scenarios 1 and 2, but according to the description in the text (l 308-316), they only include the effect of increasing recharge, not the impact of increasing ET by meeting unmet agricultural demand. If the results include the impact of meeting unmet demand and having that go to ET, that needs to be stated clearly on l 308-316—and I would argue that’s not an appropriate and even misleading simulation, since it presumes increased subsurface storage with no increased ET by irrigation expansion. Figure 5 makes it look like there's no impact of the scenarios in annual flow, which I find hard to believe if you're increasing ET significantly to meet unmet demand. As presented, figure 5 presents an overly optimistic scenario of the impact of meeting unmet demand since only the partitioning of flow from infiltration excess overland flow to gw recharge is simulated, not the impact of increasing ET by meeting unmet demand. The authors say they’d need to do a complicated sw-gw flow model with pumping to simulate the impact, but they could simply remove the unmet demand from the GW store in SWAT, no? otherwise, I think Figure 5 is not publishable"

I agree with the above comment, and I don't see it addressed adequately in the responses. The scenarios show increase in baseflow beyond the base case, but groundwater extraction would lead to a decrease in baseflow in the irrigation months. So Figure 5 is incorrect, especially in the months that irrigation is occurring.

I also do not see responses to the following questions:

"The definition of the seasons is confusing. The terms hot season, dry season, rabi, monsoon, are used without definition. For the scenarios, is the hot season the kharif season, or a third cropping season? The seasons need to be defined, with months of each in parentheses.

The hydrological terms are confusing and inconsistently used. “Surface runoff” is defined by the authors as what’s left after ET and infiltration on the hillslope, before the water reaches the stream (L 209), but I think they a really defining it as the direct runoff produced by the SCS curve number (also known as quickflow, which is equal to infiltration excess overland flow if there’s no saturation overland flow or subsurface stormflow). Direct runoff computed using SCS is not what’s left after evaporation and infiltration—it’s what’s left after infiltration. Water that’s left after ET is recharge, which can eventually become baseflow. Usually, surface runoff is defined as the total flow in a stream, including baseflow and direct runoff. In the abstract and L 330 they refer to “net gw recharge”, but I didn’t understand the term, since all GW eventually becomes streamflow or is used for ET by pumping (which I don’t think is included in their model). The authors need to very carefully define their hydrological terms and make sure they are consistent with the hydrological literature"

I commend the authors for the additional simulations done to respond to reviewers queries. There are two things I would want to the authors to address prior to publication:
1. The water balance in the additional simulations is unclear. The cumulative water budget of the system should close irrespective of the scenarios. I tried doing that by adding all base flows for Scenario 2 additional pumping, and comparing it to the case of no pumping ..the difference should be the irrigation water. However the numbers did not match up.A water balance would help clarify that.
2. The Discussion section is really brief, and the significance of the additional simulations don't show up there. What do these additional simulations signify? A broader discussion on caveats and limitations of the study is also needed given the new simulations