Rainwater Harvesting for Irrigation of Tennis Courts: A Case Study
Round 1
Reviewer 1 Report
This is my second review of the same manuscript. The authors have complied with my earlier comments and on my part I do not see any additional elements for improvement. I recommend publishing the text in its current wording.
However, I cannot highly rate the "performance" itself because of its more technical than scientific sound. However, I believe that the topic may be potentially interesting for some Water readers.
Author Response
The authors would like to thank the reviewers for their comments and suggestions.
Regarding the additional comments by Reviewers to better improve the final text, all suggestions were taken into consideration. The reply to the reviewer’s comments and corresponding modifications are detailed in the new version presented. The revised text is returned with the alterations marked.
This version has been resubmitted to a professional proofreader.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper adresses and contributes to an important issue of water-related challenges in urban areas, sustainable water use and also aspects of multi-functionality of areas.
Some comments and suggestions:
Line 45/60: potentially specify pluvial flooding? And also link this to issues of urban stormwater, that leads to challenges also in dry areas that are also not accustomed to such abrupt issues of intense rainfall (and runoff).
Line 75/100: specify what does covered mean. With what are the courts covered? Do you refer to the green "tent" on figure 1 and courts inside this when you talk about covered? So this can then be classified as roof water if it is the water gathered from this roof that will be used?
I suggest making this clearer in the text througout that the paper adresses the topic that sports facilities that consume large quantities of water, whether it is e.g. used to irrigate or as a dust-binding agent on clay tennis courts and that often such sites have also larger covered areas for both the activities themselves as well as for spectators, changing facilities etc. And thus, collecting and also using (in face of also stormwater risks) such rainwater falling on these roof surfaces for irrigation use is relevant.
Line 107: monthly time steps seems a bit course when working with rapid extremes, but I assume for water quantity dimensioning it should be ok. Consider rephrasing some.
Line 190: Reference is made to the first flush that has to do with also issues of water quality. I suggest elaborating and incude also a reference and as to why this is desirable in some cases and elaborate a bit more clearly why this is not considered nessesary in this case. That would make it easier to also assess in other cases if that should still be included. Is it here e.g. because little pollution is forseen or that the water is to be used to water the clay, i.e. just make a bit more clear what "the intented use" mean to explain.
Line 226: "...payback period for this investment of around 11.9 years can be 226 estimated, which is a value that is considered very interesting" This should be elaborated or rewritten. Why is this consired very intersting and by whom? (you the authors?).
On a general note; the discussion and implications of the results could be a bit more elaborated. The thinking of use of water from e.g. tennis court (roofs) is not new in itself. How does these results compare to other results and and what does the results contribute to in terms of (e.g.) sustainable urban water use/management.
Author Response
The authors would like to thank the reviewers for their comments and suggestions.
Regarding the additional comments by Reviewers to better improve the final text, all suggestions were taken into consideration. The reply to the reviewer’s comments and corresponding modifications are detailed in the new version presented. The revised text is returned with the alterations marked.
This version has been resubmitted to a professional proofreader.
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The English throughout needs to be extensively edited to improve the readability. I recommend hiring a proofreader as I have picked out a couple of examples of words and sentences that need to be changed in my specific comments, but it is not my place as a reviewer to identify them all.
The structure needs work with content from the methodology needing to be moved to results and vice versa.
My primary concern regarding the research is the use of monthly timestep for a simulation. Fewkes and Butler (2000) identified that simulations with monthly time steps may provide an inaccurate evaluation of the RWH system water-saving performance and suggest using the daily time step resolution for such an evaluation. This is especially pertinent as climate change will result in extreme rainfall events, which may quickly fill the RWH tank. In addition, the paper states that this type of system will reduce flood peaks in both the abstract and conclusion but does not demonstrate this in the results; an hourly timestep (preferably 5 min) would be needed for this type of modelling.
Abstract
Line 8 – Replace ‘the present’ with ‘this’.
Line 9 – What ‘different’ scenarios? Worsen, in what way, in terms of rainfall or temperature, what is relevant to this research?
Remove s from RWHSs in all cases.
Line 15 Replace adequate with suitable
Line 15-17 Rephrase sentence
Too much of the abstract focuses on the background (Line 8 -19) rather than information relating to this study(19-24). The abstract needs to give a little more detail about the novelty of the work and methodology. What RWHS has been implemented, you give no details.
Introduction
Line 52 change to for ‘non-potable purposes’
Again most time is spent on climate change; more reference is needed to the success/failure of RWH projects in Portugal and the Mediterranean and the application of RWH for irrigation of sports facilities around the world (for example, Burszta-Adamiak and Spychalski 2021). Also, a literature examination of how you would assess the success/failure of such an intervention is needed, especially if you are examining stormwater management.
Line 60 What is exceptional rainfall?
Materials and Methods
What is the variability in demand, is it recorded by the ETC?
Line 87 Show the covers in Figure 2 as well
Line 87 Are the covers permanently closed in times of rainfall?
Line 106 If you use coefficients, you need to mention them now as I do not know how you obtained 2,830 m3. Where are the water losses coming from?
Does Table 1 take into account climate change? If it does, what climate change projections is it using? If it doesn’t, how will climate change impact the values?
The monthly consumption data should be moved to results.
Results
The sizing of the tanks should be moved to the methodology.
Line 155 What type of simulation model are you using? Is it Yield After Spillage? Are you using a monthly time step? How long is the simulation time, over how many years? A monthly model would not be very accurate and cannot measure flood peak reduction as you claim in the abstract. What is the sensitivity to rainfall and demand if you get a particularly wet or dry summer?
You mention dampening flood peaks in both the abstract and conclusion, but you never demonstrate this; what if the RWHS is full at the onset of a significant event, then there will be no runoff reduction.
Table 3 The headings of this table are unreadable.
Line 197 What do you mean by ‘interesting’
Reviewer 2 Report
The manuscript shows the advantages of collecting rainwater to minimize the use of potable water for irrigation of the tennis court, and is generaly interesting.
However, after reading the title, I hoped that the introduction would be a bit different. The authors should present in the introduction what the problem of rainwater retention in cities looks like, provide some numerical data on the scale of Portugal or Mediterranean countries. Why was the tennis court chosen and why are these areas particularly important for rainwater management in urban areas?
L 119: add a blank line between the table and the text
L 144: add a space here - 52m3cisterns.
Table 3: please expand the header row a bit: this hyphenation makes the table unreadable
L 160: add a blank line between the table and the text
L 177: insert the superscript in m3
Reviewer 3 Report
The manuscript presents a hypothetical rainwater harvesting system for irrigating tennis courts in a Mediterranean climate. For me, the manuscript lacks any significant scientific novelty to warrant publication in an academic journal. The conducted exercise may be of interest to practitioners and I would encourage the authors to disseminate the work via more appropriate channels.
