The manual describes the interdisciplinary approaches and results developed in the TRUST project, which are particularly applicable to arid regions. The approaches range from hydrological models, stakeholder and conflict analyses to concepts for water supply and wastewater disposal.

The manual is aimed at decision-makers and people who work in the water sector. It is intended to support the development and implementation of locally adapted solutions for sustainable water management. At the same time, it presents the results of the joint project TRUST (“Sustainable, fair and environmentally sound drinking water supply for prosperous regions with water shortage: Developing solutions and planning tools for achieving the Sustainable Development Goals using the river catchments of the region Lima/Peru as an example.”). The approaches presented combine natural, engineering and social science expertise from research and practice, starting at the local level and scalable to the level of catchment areas. The approaches are based on the areas of “water resources”, “water use” and “water management”, which are closely linked and allow the development of integrated water management concepts. In each of the areas, an information base is first established; analyses and concepts are linked to these. Finally, key lessons and recommendations are developed.