Population growth and climate change has a huge impact on water availability. To ensure a secure water supply, water-reuse concepts and its implementation are gaining more and more importance. Additionally, water saving potentials to optimize the drinking and water reuse availability have to be considered. However, limited spatial planning opportunities and missing regulation to provide treated wastewater according to the “fit-for-purpose” principle are often hindering its application. Some countries, such as the USA or Singapore, have been leading the way for decades in implementing water-reuse concepts and in treating wastewater for potable and non-potable reuse. The wastewater treatment technologies are currently providing solutions for an adequate provision of reclaimed water. Consequently, the opportunities for water reuse are given, but the challenge is largely in the implementation, which becomes necessary in water-scarce regions. This perspective is thus presenting the current possibilities and challenges of wastewater reuse with respect to existing examples of implementations but also shows the need for action in the future. The relevance of this topic is also underlined in particular by the Sustainable Development Goals (SDG), especially Goal 6 which is related to “Ensure availability and sustainable management of water and sanitation for all”.

Water scarcity is a huge challenge for industrial and urban developments. As such developments are based on a secure water supply, strategies to ensure the required water quantities must be put into effect. In this context, sustainability is becoming an increasingly important factor due to the worsening of pollution and climate change. The integrated industrial–urban water‐reuse concept (IU‐WA‐RE) links gray and green infrastructures by providing reuse water for different infrastructural purposes. Municipal and industrial wastewater is treated separately in different water resource recovery facilities. As a baseline the SEMIZENTRAL approach with the Resource and Recovery Center (RRC) and the Industrial Wastewater Management Concept with a focus on Reuse (IW²MC→R) for the industrial wastewater treatment are taken into account. These approaches are new concepts for wastewater treatment “fit for purpose.” IU‐WA‐RE combines the water‐reuse concepts by linking reuse water flows between the urban area and the adjacent industrial park, but focuses not on a production internal water reuse. The concept is designed to offer a holistic strategy to increase the water‐reuse potential and thus the water resources. It offers a solution to cover the lack of water requirements in urban areas. It is therefore possible to drive sustainable urban developments.Practitioner points: The water‐reuse potential increases enormously by combining industrial and municipal wastewater flows. Industrial wastewater should be treated “fit for purpose” and applied in the urban area since the municipal wastewater is not sufficient to cover its own water requirements for infrastructural purposes. Water‐reuse for infrastructural purposes increases water resources. The application of reuse water drives sustainable urban developments.

New industrial and urban developments in water-scarce regions are often inhibited by their high demand for water from natural resources. In addition, there often is a lack of water for purposes that contribute to an improved quality of life, such as urban green spaces. Therefore, the integrated industrial-urban water-reuse concept presents a strategy by linking and reusing treated industrial and municipal wastewater flows to increase urban water-reuse potentials. The concept of combining different reuse water flows, from wastewater treatment plants from industrial parks, aims at significantly increasing the water-saving potentials compared to a separate consideration of the industrial wastewater flows.

Lima is the second-largest capital of the world located in a desert and already faces water scarcity. Here, more than 30% of the population is supplied by only 2.2% of the national water resources. The urbanization process has an informal nature and occurs at a very accelerated rate. These new settlements lack water infrastructure and access to other services. The objectives of this study are to quantify changes in the urban landscape of Lima Metropolitan Area from 1990 to 2021 to propose a water-sensitive urban plan by detecting changes, urbanization trends and identifying alternative water sources. The trend suggests a future constant increment of the urban areas, diversification of the landscape and more equally distributed land cover. Lima has more disconnected settlements and more complex shapes of urban patches nowadays. The landscape is also more mingled, but cracked. Overall, the trend is to become more disaggregated, demanding small and scattered water solutions. The WSUP includes the implementation of treatment plants in new multi-family buildings, hybrid desalination plants at the coast and parks with fog collectors on the hills. Additionally, these solutions will require the beneficiary community and the local authorities to work together in the planning and maintenance.

Requirements for wastewater management and water-reuse concepts concerning sustainability are gaining greater importance, especially in times of climate change. Industrial park developments are often hindered due to water scarcity. Thus, nowadays, the reuse of wastewater is becoming more and more important to increase the availability of water and to enable new developments. The sustainable Industrial WasteWater Management Concept with the focus on Reuse (IW2MC → R) provides a solution strategy to produce reuse water from industrial wastewater within production plants. To achieve sustainability, certain requirements are essential since the reuse water can be provided directly via an optimized wastewater treatment process for subsequent use. Hence, it is then ‘fit for purpose’. This enables a more efficient application of reuse water. Furthermore, due to environmental issues, it is important to construct space-saving water resource recovery facilities for reducing land consumption within industrial parks.