Review of 'Tacit knowledge in water management: a case study of Sponge City'

In the introduction of this study, the authors state that universal challenges experienced by most pilot cities in China’s Sponge City Initiative result from knowledge gaps across different sectors and disciplines. They then state that difficulties regarding the communication of knowledge between actors are a root cause of challenges related to policy, resources, governance, and individual and societal, attitudes and behaviours. From this point, they note that tacit knowledge is especially difficult to communicate with others (without explaining the relative value of tacit knowledge).

With this reasoning, they go on to describe different perspectives on tacit knowledge and choose to investigate the use of relational, somatic, and collective tacit knowledge in the Sponge City pilot project. Based on structured interviews with 38 people working in the project, they seek to identify barriers and pathways for communicating tacit knowledge. Finally they discuss the role of urban planners as knowledge brokers between actors in the process. They conclude that improving relational and somatic tacit knowledge transfer is most important in the context of the Sponge City Initiative and that urban planners are best suited to act as brokers of tacit knowledge.

The study is valuable in helping to identify some of the barriers to effective communication among actors as described by the interviewees. Framing these barriers in the context of perspectives on tacit knowledge is also potentially valuable but requires additional attention in the manuscript to be fully realized.

First I suggest the authors clarify how they were able to determine that the barriers to communication related specifically to tacit knowledge and did not also include explicit knowledge. How did they filter explicit knowledge from their analysis and verify that all knowledge transfer analysed was of tacit knowledge? For example, on page 8 the authors write “What also made knowledge transfer and learning difficult, is the inability of actors to adequately explain a concept to another individual who has a different knowledge background. Many said that they either could not find the right way to get their messages across, or their colleagues could not perceive the need for additional explanation or understand the point of confusion.” In this case how did the authors confirm that the knowledge the actor was struggling to transfer was tacit? Could they not have been struggling with the transfer of explicit knowledge from their academic training? The barrier would then appear to be the actor’s inability to adequately explain rather than the tacit nature of the knowledge. The other individual could better access the knowledge (if necessary) through another learning mechanism.

Other comments:

Page 1: I recommend deleting “by mobilising stakeholders to ensure good public health and improve social, economic, and ecological outcomes” from the first sentence of the Introduction because it suggests mobilizing stakeholders is the main aim of SUWM. But it is only one component.

Page 2: There is too large of a jump between the paragraph starting with “Since it began in 2014”and the paragraph beginning “Tacit knowledge is difficult”. There needs to be a link to go from "knowledge gaps" mentioned in the first paragraph and tacit knowledge. Why focus on tacit knowledge in this paper... not only because is neglected. What is the special value of tacit knowledge that makes its transfer essential to the success of collaborative projects?

Page 9 Section 5.2: I do not see in the text of this section how the exchange of somatic knowledge was assessed. The examples given relate mainly to language used and understood, which is more similar to relational tacit knowledge described in the previous section. Where is the connection to limitations imposed by the capacity of the human body?

Page 10 Section 5.3: I see no reporting of results in this section that derive from the interviews. What is the link to tacit knowledge and the methods applied in this study?

Page 10, sentence ending in “but it is still necessary to consider the means to guide a shift in the culture that governs the relationship between water professionals”: Is the goal to change the culture? I understood that it is important to understand the culture in the effective exchange of collective tacit knowledge but not necessarily change it.

Page 11 Section 5.4: This section presents a valid argument about the role of urban planners but makes no mention of the role of tacit knowledge. Nor does it link to the previous sections of the paper. Please make the linkages and explain how you arrived at the selection of urban planners as preferred knowledge brokers based on the previously reported results.

Page 11: The sentence “Actors in other stages of the project may or may not have a direct relationship with the plan makers, but they are all indirectly linked with planners via the documents they produce. However, a tie between planning and design may weaken for various reasons” is repeated again on page 12.

Conclusions, referring to the sentence “This paper demonstrated the value of mapping different types of tacit knowledge as the basis for building stronger interdisciplinary collaboration to achieve sustainable urban water management”: I do not find the paper to do this, but I agree this value could potentially be demonstrated by making clear connections between the sections on different forms of tacit knowledge and the integrative role of urban planners.

Conclusions, referring to the sentence “This study is therefore the first step in the investigation of the ways water professionals communicate across disciplines and fields in order to achieve sustainable urban water management”: If this is the goal of the paper I recommend you extract a set of hypotheses (or research questions) that emerge from this first step and can be further investigated in the next.