Scientific Evidence behind the Ecosystem Services Provided by Sustainable Urban Drainage Systems

Round 1

Reviewer 1 Report

Dear Authors,

I have read this review paper with great interest and my opinion is that the paper needs further elaboration before publishing.

The purpose of this review is stated to show: “which of the ecosystem services attributed to SUDS have been empirically demonstrated and if their performance for different ES varies according to climate, a determining factor in the development of ecosystems.”

In the text below I have tried describe areas of major conern.

General

The authors start with a general idea to show which ecosystem services attributed to SUDS have been empirically demonstrated and basically  concludes that SUDS  are  drainage elements focusing on quantity and quality within a regulated stormwater context.

The general conclusion seem to be that SUDS treated as isolated local elements have not been assessed per se to determine how they contribute to other ecosystem services.

I believe the framing of review should be contemplated and elaborated to encompass that when SUDS were first introduced on a more systematic city level, see e.g Stahre 2008 , it was obvious that intangible values where part of the overall analysis regarding the implementation of SUDS. The characteristic feature of sustainable urban drainage is that quantity and quality aspects of the runoff are handled together with various social aspects of the drainage. In the sustainable approach, stormwater is looked upon as a positive resource in the urban landscape.

At least from a general point of view, the authors should try to frame how blue and green elements in combination are used to green cities today and possibly also  shed some light on how academic literature is capturing trending on capacity building of  ecosystem services  of the city. Please elaborate how water, and in particular stormwater is contributing to this ambition.

The technical components contemplated in this  review are limited to  rain barrels, pervious pavements, soakaways, infiltration trenches, bioretention systems, green swales, filter strips, infiltration ponds, detention ponds, retention ponds and artificial wetlands. The authors need to explain why green roofs, roof gardens, urban cultivation and green walls are not included in this list. Would it be possible for the authors to include at least green roofs and walls in the review?

Now some more detailed questions

Line 131 The Köppen climate chart needs to be illustrated with a map also displaying how papers were describing each region.

Line 150. Please explain and exemplify what is meant by this paragraph and the following sentence “therefore, we reviewed the results to reclassify the publications according to  the type of observed ecosystem service.”.

Line 173. Please explain more in detail how the figure is constructed.

The figure shows the number of articles dealing with ecosystem services in the SUDS by climatology. Why do you want show the column on the left i.e. the number of articles according to the search. I believe you are not using these articles for further examination. Figure 2 requires further elaboration and explanation.

Would it also be possible to construct another a figure showing the different SUD elements sorted according the climatology type? This would help understanding the evaluation beginning at line 177. In its present state the evaluation is difficult to follow with regard to especially climate type and use of different SUDs. Please go through this paragraph and make relevant revision.

Line 677. The paragraph below has to be further elaborated:

“Although vegetated swales [110] and some permeable pavements can act as temperature regulators [22] in temperate climates, other SUDS can increase greenhouse gas emissions [47] [206] [207] [244] and sometimes can have a climate warming effect in cold climates [154] [252]”

In some case I believe the references merely state that when organic material is decomposed it will lead to the release of carbon dioxide. This on the other hand is not always a process based on fossil organic material and in the context of SUDS it may actually represent a carbon neutral process. Please go through this paragraph and try to set the process in a more specific context.

After revision of the paper please go through your conclusions and revise them accordingly

Author Response

Dear Reviewer,

We wish to thank you for your careful reading of our manuscript and the insightful comments and suggestions. We believe that the constructive comments made have resulted in the improvement of the text of this paper. We much appreciate the help with the texting and the detailed review of the manuscript. As a result of these changes, we believe that this revised version has substantially improved the original manuscript. Please find detailed responses to each of the comments below.

Yours sincerely

Author Response File: Author Response.docx

Reviewer 2 Report

Author Response

Dear Reviewer,

We wish to thank you for your careful reading of our manuscript and the insightful comments and suggestions. We believe that the constructive comments made have resulted in the improvement of the text of this paper. We much appreciate the help with the texting and the detailed review of the manuscript. As a result of these changes, we believe that this revised version has substantially improved the original manuscript. Please find detailed responses to each of the comments below.

Yours sincerely

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Dear Authors,

It has been a pleasure to read and contemplate the content of your manuscript. The revised version has indeed been improved and provides an in-depth analysis of the integration of SUDs in the urban environment.

One small thing:  Line 850,  the words “in temperate” are written twice.