**1. Introduction**

The world is rapidly urbanising. From 1950 to 2020, the population residing in cities increased from 0.8 billion (29.6%) to 4.4 billion (56.2%), and recent projections point towards it could reach 6.7 billion (68.4%) by 2050 [1].

The latest IPCC report highlights that global net anthropogenic GHG emissions in 2019 were 12% higher than in 2010 and 54% higher than in 1990 [2]. The implied global emissions by 2030 exceed pathways consistent with 1.5 ◦C and are near the upper end of the modelled pathways range, which keeps temperatures likely to limit warming to 2 ◦C [2]. In urban environments, observed climate changes impact human health, livelihoods, and critical infrastructure systems, which will be increasingly vulnerable if their design does not consider changing climate conditions [3].

Controlling greenhouse gas emissions and conserving dwindling water resources while feeding and serving a growing population is, in fact, a daunting task [4].

Whilst in the last century, the population grew three times, water consumption increased six times, following the average level of income, the evolution of habits, and a different demand for food [5], increasingly dependent on water, which represents, on a global average, about 70% of water consumption [6]. The area needed for irrigated agriculture increased, and consequently, so did the water needed for its production, which in turn

**Citation:** Vinagre, V.; Fidélis, T.; Luís, A. How Can We Adapt Together? Bridging Water Management and City Planning Approaches to Climate Change. *Water* **2023**, *15*, 715. https:// doi.org/10.3390/w15040715

Academic Editors: Alban Kuriqi and Luis Garrote

Received: 11 January 2023 Revised: 6 February 2023 Accepted: 9 February 2023 Published: 11 February 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

is a competitor of the water required for other uses, such as industry, hydroelectric power production [7], and urban.

Furthermore, managing water resources, essential for human life, economic activities, and ecosystem functioning faces enormous challenges in a changing climate. It is known that water availability is not evenly distributed in the territory or in time [8]. The effects of climate change, namely through extreme phenomena such as droughts or floods, make the management process even more complex. Extreme hydrological events such as prolonged droughts and floods are increasingly frequent, creating great uncertainty about cities' water security [9]. This context can compromise the objectives of the United Nations Sustainable Development Goals (SDGs), especially the SDG11 Sustainable Cities and Communities and the SDG6 Clean Water and Sanitation [10].

In the "excess of water" dimension, it can be seen [11] that urban areas are particularly vulnerable to strong rainfall episodes due to their impermeable surfaces (such as roads, parking lots, and roofs) that prevent rainwater infiltration and, consequently, increase surface runoff and the risk of rain flooding [12]. Urban sprawl and a potential lack of water storage capacity in rainfall peaks lead to an insufficient drainage capacity of the water system, resulting in rain floods [12,13].

In the "water scarcity" dimension, i.e., when demand exceeds availability, the health and wellbeing of citizens, the quality of the urban environment, and socio-economic development are put at risk [8]. Related to the phenomena of scarcity due to climate change, the adoption of water reuse or rainwater harvesting efforts is critical, especially when considering urban development needs in warmer climates, the decline of water resources, the difficulty of transporting water between basins, and efforts to increase sustainability in urban planning and management [14–17].

On the one hand, water service providers need help with new problems concerning adaptation to climate change and the simultaneously evolving context, such as population growth, increasing urbanisation, and changes in consumption patterns [18,19]. On the other hand, critical aspects of managing the supply/demand balance are related to the dynamics of the territory and how the spatial planning and demography introduce new needs and consumption patterns [20], as well as new threats. For example, spatial distribution and consumption habits in the Barcelona region led to water consumption about ten times higher in peripheral areas (typically houses with lawns) compared to the urban core area with multifamily buildings [21]. Another challenge has to do with how these drivers call land planning for new solutions that integrate not only the necessary resilience to extreme drought and flood phenomena but also contribute to positive externalities at the level, for example, of blue and green infrastructures, enabling a better urban environment and improving the quality of life of populations [22–25]. Adapting cities to the effects of climate change on the water cycle is, therefore, a pressing issue. This involves assessing the adequacy of existing (often obsolete) infrastructures and their resizing and adaptation, whether in terms of the asset or how it is operated. Given the complexity of these challenges and the issues that must be addressed, including how and when they should be tackled, it requires the involvement of different actors in urban planning and water governance as well as risk management [26–28].

Entities responsible for managing the urban water cycle and associated social and ecological needs (water services, regulators, legislators) are thus called upon to rethink their decision-making processes [29]. However, they cannot act alone. The challenges of climate change reinforce the importance of the interrelationship between the management of water management services and the entities responsible for the planning and management of the urban territory [20,30]. The relative location of the economic activities that consume/reject water and the socio-economic relationships are aspects to consider for sound management of water resources, considering the supply, demand, and sustainability of the entire urban water cycle.

Faced with emerging water management challenges in cities, Marlow et al. ([31], p. 2) propose the overarching concept of sustainable urban water management (SUWM) "as an

aspiration, SUWM reflects a generalised goal to manage the urban water cycle to produce more benefits than traditional approaches have delivered". Hurlimann and Wilson ([30], p. 1) consider that even if the concept of SUWM is not definitively enshrined, it "implies the consideration of climate change and the inclusion of both supply and demand side initiatives".

From what has been said, given the context of rapid change that is approaching, reaching "sustainable urban water management" is necessary [30].

While several studies have covered different aspects of the relationship between climate change, spatial planning, and the water cycle over the last few years, to our knowledge, there has yet to be a study that identifies, catalogues, and integrates consolidated expertise in these fields. Thus, this article aims to clarify and systematise existing knowledge, to systematise learnings and gaps, and to point out approaches that need further development. It undertakes a literature review focusing on two major questions: (i) What are the main themes addressed by contemporary research on sustainable urban water management? (ii) How is the scientific community addressing the collaboration between water management and urban planning agencies, and how is the relationship between climate change and the urban water cycle considered?

In this context, research and related dissemination become increasingly essential to support decision makers, water service providers, and communities for more robust climate change adaptation, infrastructure design, and operation in a potential new urban landscape. The article is organised into five sections. Following this introduction, Section 2 describes the methodology used to undertake the literature review. Section 3 presents the results, and Section 4 discusses the findings, insights, and gaps. Section 5 presents the main conclusions.
