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

The study is exploratory research that explores the characteristics of tacit knowledge empirically in China’s Sponge City pilot project by identifying the extent of using three types of tacit knowledge - relational, somatic and collective tacit knowledge, falling along a spectrum of weak to strong. The research analysed qualitative data obtained from semi-structured interviews with different practitioners in the Sponge City project, applying both inductive and deductive coding processes. As the first step in examining interactive communications among a diverse range of water specialists, the results provide groundwork in favour of mobilisation of tacit knowledge in the Sponge City project, which has been gradually upgraded as a national action in China lately, at various locations of Chinese cities. The insights from practitioners also help identify future research needs for sustainable water governance in China.

The manuscript is well-written, timely and relates to an increasing global interest in Nature-based Solutions and a burgeoning concept of China’s Sponge City. I highly appreciate the study's originality and the sociological analysis of knowledge transmission in the Sponge City program. Nevertheless, I believe some revision is still needed; the following concerns should be considered critically to make this review more logical, profound, and straightforward.

Major points

The introduction (1-3) lacks a clear structure. Elements of tacit knowledge, sustainable urban water management, and the Sponge City concept are loosely connected. The reason why the Sponge City project is considered a sustainable urban management practice and the knowledge context of Sponge City is missing. The term “knowledge brokers” described in the results should also be introduced in the introduction.

The methods (4) are not sufficiently clear. Which cases of the Sponge City pilot project were selected? The geographical scope of the manuscript could also be more explicit as Sponge City has been implemented in many Chinese cities; each of them faces different water challenges and has different water governance dynamics. How were interviewees identified? How many were the interviewees in each stakeholder group (U, G, C, P; and no actors from public/civil society?)? How were the three rounds of the coding process carried out? Besides, “the actors interviewed can be divided into five groups based on their professions”, but there are only four (U, G, C, P).

For the results (5), the features and characteristics defined and discussed with the analytical framework were not well illustrated. There is a lack of sample quotes of knowledge exchange between actors regarding site-specific actions in pilot Sponge City (again, which city is chosen?), as Sponge City is an umbrella project that involves a series of engineering and/or non-engineering measures, e.g., river/lake ecological restoration, upgrade of sewage system, rain garden, green roof/wall, etc. Different stakeholders are involved to a different extent in different initiatives (and are all these initiatives top-down?). I failed to find data analysis compelling about how different tacit knowledge is distinguished, identified and categorised in a sweeping statement of “Sponge City”. I suggest breaking down an overarching Sponge City program and adding a summary table composed of each tacit knowledge type (relational, somatic, collective tacit knowledge), keywords (direct quotes from interviews) and features extracted, the corresponding percentage of interviewees’ expression, etc.,

The role of urban planners was described both in 5.2 and 5.4 as vitally important to guide the Sponge City project. I found their position a bit confusing. In China, some urban planning institutes are “public service units” (shiye danwei) providing public services alongside core government, and some are private companies bidding on public construction contracts. Their relationship and interaction with the local government thereby vary, as well as their abilities to play an “integrating role”. With the new national policy of River Chief System (Hezhang zhi) launched in 2016, the newly appointed River Chiefs (He-zhang) tend to take the leading, coordinating and facilitating role of all projects related to surface water bodies under their jurisdiction (but the implementation of River Chief System also depends on locations).

5.3 analysed a collective tacit knowledge rooted in Chinese culture and China’s modern political system. It will be good to add the “top-down information asymmetry”, in which higher authorities in China often strategically issue ambivalent orders or give ambiguous information to their subordinates, which may induce national plans poorly enforced at the local level, but also gives the flexibility of implementation and encourage policy innovation. In addition, it is also worth describing the evolution of Chinese water culture that governs the relationships between water professionals – from overall harmony between humans and nature in ancient times to intensive water-engineering projects to explore water resources for human use after the founding of the People’s Republic of China in 1949, and to (finally) a shifting focus on “ecological civilisation” from 2012.

At the end (6), a more comprehensive conclusion section would be desirable. As the list of pilot Sponge City continues to extend in China, there is a need for guidance on improving the complex governance structure of the Sponge City program. Though remaining a preliminary set and context-specific, the research findings in the manuscript constitute a good base in this regard. Some practical suggestions to resolve the present communication barriers would be helpful. I have no doubt it will be of interest to many researchers and policymakers.

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.