The literature review in the Web of Science database to identify the principal aspects of resilience regarding UDS management in worldwide public policies from 2009 to 2019 yielded a total of 1,548 articles. Table 1 summarizes the results for each keyword combination.

Figure 1 illustrates the contributions per country for urban resilience, urban drainage & resilience, and urban resilience & infrastructure.

In terms of resilience studies, researchers from the USA led, followed by England, Italy, and the Netherlands. In general, the number of publications per year is growing, except for the “resilience & stakeholder participation” combination, which has decreased since 2015. This review indicated a lack of research in this area in Latin-American countries. Mexico is the leading country, with <20 articles. In Colombia, research efforts have focused on Risk Management and the emergence of the urban resilience concept. The results of our main findings regarding local strategies on resilience in UDS are presented in the following subsections.

Many researchers believe that the transition to sustainable water management has been slow (Brown et al., 2007; Cettner et al., 2013; Dhakal and Chevalier, 2015; Jiménez Ariza et al., 2019). A critical obstacle has been the absence of a comparative evaluation tool that facilitates communication between stakeholders to develop long-term policies and improve sustainable water management between cities (Gleick, 2003). Additionally, urban water managers lack a clear vision or objective that can lead to the development of a sustainable city. Responding to the previous, Brown et al. (2009) developed an urban water transition framework. This framework acts as a conceptual tool to communicate the development of a transition policy and the comparative evaluation at the macro level of the city. It has three parts that are in parallel, (i) the cumulative socio-political drivers that (ii) characterize the city and (iii) the service delivery functions. The cumulative socio-political drivers range from “Water supply access and security,” then “Flood protection,” to “Inter-generational equity, resilience to climate change.” The city begins as a “Water supply city,” then a “Drained city,” finally a “Water sensitive city.” The service delivery functions range from “Supply hydraulics,” then “Drainage, channelisation,” to “Adaptive, multi-functional infrastructure and urban design reinforcing water-sensitive behaviors.” For more detail see Brown et al. (2009).

Lundqvist et al. (2001) proposed the concept of “hydro-social contracts,” which are dominant values or implicit agreements between the community, government, and companies on water management. This framework contemplates the temporal, ideological, and technological contexts in which cities transition to sustainable water cities, considering variables such as specific-to-the-city historical and socio-political dynamics.

Zhang and Li (2018) carried out a study at the city level regarding resilience in public policies and technical regulations. They found that the action considered most important in most urban resilience management research was to strengthen the institutional agreements of elastic urban structure. These agreements seek to guarantee the adoption of measures toward resilient cities, hence having the potential to lead to flexible or innovative solutions. Additionally, the global level metropolitan strategies have been recognized as key to addressing contemporary urban challenges (Finco and Nijkamp, 2001; Pinson, 2002; Gleeson et al., 2004; Davidson and Arman, 2014; Nguyen et al., 2018).

Henstra (2012) researched the process of policy development for resilient cities in two Canadian towns with extreme climates, Toronto and Halifax. The author examined the elements of the urban climate adaptation policy, mainly focusing on adaptation, one of the climate change response policies. Henstra (2012) observed that the critical step in developing adaptation policies was determining climate hazards, vulnerability, and risks from current and future climate, then identifying and prioritizing the risks and selecting the most appropriate responses. This step requires expert knowledge and specialized information analysis, for example, in socioeconomic, hydrometric, and meteorological data (Fünfgeld, 2010). Another crucial element identified was internal steering committees to adapt policies and integrate principles into existing policies, official community plans, and programs, constituted by individuals representing the departments of environment, public health, and water (Henstra, 2012).

The formulation of adaptation policies of both Toronto and Halifax was initially based on the construction of information-based tools to visualize the current state of climate change and generate ideas to reduce vulnerability. Then, through forums, obtain public feedback on the formulated ideas. For example, in Toronto's case study, the adaptation committee aimed to project adaptation strategies. Their first initiative was to develop a panel of experts. Government scientists, university researchers, and non-governmental organizations attended this panel. After this panel, the committee led workshops with focus groups and community information sessions for several months. The main objective was to motivate decision-makers and the community to generate ideas and provide feedback on previous related projects. With this process, Toronto obtained short-term adaptation actions toward transforming into a resilient city (Henstra, 2012).

Davidson et al. (2019) developed a methodology to evaluate the inclusion of socio-ecological resilience within the urban planning practice. The authors reviewed local strategies such as “Our People, Our Place” of Greater Manchester in the United Kingdom and “The 30-Year Plan for Greater Adelaide: Living Adelaide” in Australia. They found that the only strategies involving socio-ecological resilience were “One New York: The Plan for a Strong and Just City” (OneNYC) and the Melbourne Plan. The authors used these plans as a study case. They noted that the dominating concept in both plans was engineering resilience, suggesting that it is easier to translate engineering resilience into planning instruments. However, they noted that these plans lacked the essential components of resilience (e.g., economic resilience). Because both plans use the resilience concept essentially as a response to climate change or natural disasters, the strength of the concept is reduced. The use of resilience should aim to build a society and a flexible economy capable of adapting to uncertainty (Drobniak, 2012). It is crucial to highlight that Davidson et al. (2019) identified the implications of using resilience for the theory and practice of urban planning, which can potentially generate proactive policy changes and support the beginning of a new planning paradigm. The authors observed progress in its inclusion in management plans in terms of engineering resilience. However, it is necessary to continue efforts to include socio-ecological thinking to potentially provide innovative ideas for city governance.

In 2011, MWH (engineering, consulting, and construction management firm) developed a study for OFWAT, the water services regulation authority in England and Wales, to know how other countries (USA, Switzerland, the Netherlands, New Zealand, Australia, and Scotland) have implemented innovative approaches in urban drainage compared to England and Wales. Based on this information, six main characteristics were identified: (i) management responsibility; (ii) funding source; (iii) society commitment; (iv) incentives for urban drainage management; (v) regulations for urban drainage management; and (vi) urban drainage integration with planning.

Concerning management responsibility, England and Wales's privately managed urban drainage schemes do not promote public participation or work between stakeholders (MWH, 2011). The study notes that responsibility from a sole point does not promote more innovative approaches. The key is to generate decisions from a group of stakeholders with the community's support to manage the UDS better.

The financing of UDS, the sources are similar among the countries surveyed. The key here is cross-financing between different organizations, which is common for most countries surveyed except in England and Wales. The study results showed that incentives play a fundamental role compared to the legislative part by being more successful in encouraging innovative approaches. Besides, a commitment from society allows for effective public participation and good stakeholder management. These practices facilitate the adoption of innovative measures in UDS (MWH, 2011).

Regarding the regulations and standards to implement new methods in UDS, the MWH (2011) showed that their use increased when directed toward pollution control. Therefore, the change in planning regulations has served as a vehicle for change. The study showed that most countries integrate UDS into planning, mainly because UDS innovation requires a larger group of bodies responsible for urban environment. Finally, the MWH (2011) identified five lessons to implement innovative measures in UDS:

Table 2 presents the regulation and strategies related to resilience, sustainability, and UDS at the national level. Based on the findings, we observed that there are already advances and some supporting pillars. Law 1523 of 2012, from de Congress of Republic of Colombia, adopted the national disaster risk management policy and established the national disaster risk management system. Also, through it, the term resilience entered into the definition of the word adaptation (Ley 1523 de 2012, 2012). Law 1931 of 2018 determined the guidelines for climate change management. In Article 16, the government defined the National Climate Change Policy; its aim includes climate change management in public and private decisions to advance toward climate-resilient and low carbon development to support the reduction of risks associated with climate change (Ley 1931 de 2018, 2018).

In 2019, the newly elected Colombian government presented the “National Development Plan 2018–2022 Pact for Colombia, Pact for Equity” under Law 1955 of 2019 (Ley 1955 de 2019, 2019) to boost economic growth to improve the country's development. This plan has three structural agreements: legality, entrepreneurship, and equity and incorporates 12 transversal agreements to fulfill these objectives. The Pact for Sustainability (Pact IV) includes the term resilience in the following subchapters: (i) Resilient Colombia: knowledge and prevention for disaster risk management and climate change adaptation; (ii) Modern environmental institutions, social appropriation of biodiversity, and effective management of socio-environmental conflicts (DNP, 2019).

In the “Resilient Colombia” subchapter, the government proposed the details of the activities to reduce risk conditions, increase climate resilience, and limit the sectors' losses. There are also technical guidelines to analyze climatic risks and adaptation criteria in new projects, built environments, and basic sanitation infrastructure. The Ministry of Housing, City, and Territory (MinVivienda) oversees this segment, with the support of the Ministry of the Environment (MinAmbiente) and the National unit for risk disaster management (UNGRD). It also proposed the design of a public policy to reduce the risk conditions in the event of climatic variability, headed by the National Planning Department (DNP), MinAmbiente, the Institute of Hydrology, Meteorology, and Environmental Studies (IDEAM), and the UNGRD. In the second subchapter, “Modern environmental institutions,” the government identified that there is no integrated vision to promote resilient and sustainable territories between the National Environmental System (SINA), SNGRD, and National Climate Change System (SISCLIMA). Thus, they proposed to strengthen the mechanisms of articulation and coordination for sustainability (DNP, 2019). This subchapter places more emphasis on the term sustainability than on resilience.

At a local level, in Santiago de Cali, the Corporation of Valle del Cauca (CVC), the Administrative Department of Environmental Management (DAGMA), and the International Center for Tropical Agriculture (CIAT) combined technical and economic efforts in response to the global climate change management initiative and the ratification by the national government. They suggested actions to be implemented within the Comprehensive Climate Change Adaptation and Mitigation Plan framework for Santiago de Cali. Resilience is part of this plan's conceptual and methodological framework as a tool to promote the adaptation of social, economic, and environmental systems (CVC et al., 2017). These entities defined programs within each line, comprising objectives, activities, approximate costs, and goals. They proposed five programs for the integrated water resources management line, including (i) protection and restoration of water-producing areas under a scheme of payment for environmental services; (ii) water and biodiversity management guidelines update with a climate change approach; and (iii) a comprehensive rainwater management program using SUDS as an instrument to build climate change resilience.

In 2015, Santiago de Cali became part of the program “100 resilient cities” of the Rockefeller Foundation. Engagement in this program helped the city build its resilience strategy using a robust methodology (The Rockefeller Foundation, 2019). However, before the resilience strategy, the city committed to demonstrating its involvement and empowerment. Hence, the city created the “Cali Resilient” program within the “Secretariat of territories of inclusion and opportunities.” With this program, the mayor launched the resilience strategy in 2018. The strategy has five action lines: (i) education for opportunities; (ii) coexistence for life; (iii) mobility for development; (iv) sustainability for the future; and (v) planning for progress. Urban drainage is addressed within the line of action of sustainability for the future, which proposes the following two objectives: (i) to strengthen the use of the territory to preserve natural resources and (ii) to establish effective mechanisms for decision-making. They will develop these objectives through ten initiatives, five for each (Alcaldía de Santiago de Cali, 2019).

Based on international evidence, we identified the fundamental characteristics and tools used to include resilience in UDS public policies. The findings at the national level gave us a broad scenario and where to start to generate recommendations on the inclusion resilience of UDS in public policies and technical regulations.

According to the international literature review, the concept of resilience in public policies is a contemporary issue, especially in socio-ecological resilience terms. The key factors found for incorporating urban drainage resilience were summarized in Figure 2. The arrows in this figure represent that the movement of each gear is relevant for achieving urban drainage resilience, so each factor is needed. We recognized management tools, such as the urban water transition framework to support stakeholders interested in having a clear vision of developing a sustainable and resilient city in terms of urban drainage. Also, we observed that management instruments, such as metropolitan plans, contribute to making a city more efficient in initiatives execution (Davidson et al., 2019), and they must have a long-term vision. For local development, it is also necessary to consider establishing hydro-social contracts (Lundqvist et al., 2001) and evaluate if they must remain the same or change. Additionally, to implement innovative approaches in the UDS, we recommended adapting and applying the identified characteristics of countries' strategies with successful cases to facilitate resilience of UDS implementation. We identified the implications of collaborative work, the use of information tools for decision-making (Henstra, 2012), and the importance of having information in the public domain to include the concept of resilience (MWH, 2011). The use of these tool types appears to encourage more efficient processes of the cities toward resilience.

The findings at the national level evidenced pathways to update public policies, involving a multi-step process regarding local and national activities. One recommendation could be to propose a pilot project using the Santiago de Cali Resilience Strategy, choosing one program of the lines of action (e.g., Integral rainwater management program through SUDS) to develop. This part could begin with implementing engineering resilience and gradually integrating the socio-ecological component. Parallel to the above, a strategic ally of the Multilateral Banking (e.g., IDB or the World Bank) could help secure resources. This project could be scalable to a body such as the Departmental Council of Environmental Policies and Integral Management of Water Resources (CODEPARH) of the Governance of Valle del Cauca. Through this body, we could seek to replicate this strategy to other Valle del Cauca towns and, thus, give technical guidelines for the formulation and updating of public policy.

During the first two parts of the workshop conducted with experts and representatives of institutions in Cali, we introduced the urban water transition framework to open dialog and facilitate communication in terms of urban water management. We then shared the importance of the hydro-social contract updating and the main characteristics of the innovative implementation of approaches in urban drainage, emphasizing that one of the main drivers is pollution control and that culture with a fear of risk does not encourage innovation. We also illustrated the key factors identified for urban drainage resilience incorporation and the opportunities that we evidenced with the implementation of the Santiago de Cali Resilience Strategy (section Recommendations for the Incorporation of Resilience in UDS in Public Policies).

During the last part of the workshop, which consisted of group work on the proposed strategies and their socialization, the stakeholder groups suggested actions to implement the concept of resilience in UDS for the short and medium term. However, they did not identify any for the long term. Figure 3 summarizes the results of the last workshop's group activity.

From the workshop results, we identified that it is crucial to include the visualization of inter-institutional coordination in the development of the pilot project, with the definition of roles and participation of each body to generate visibility and an implementation model. We could also emphasize the planning part of the pilot project in communications with the stakeholders. Additionally, developing a project that focuses on disseminating the concept of resilience at the institutional level could create ownership and facilitate its implementation.