In cities whose structure is characterized by dense building, the extension of urban areas and the compaction of the soil, the excessive urbanization with no green spaces, the interventions on the streambeds of natural waterways (landfill) for private and public building (primarily for the creation of roads), the conversion of areas of natural flood interception into urban zones, have led to the loss of water and to a decrease in the groundwater level.

The growing needs and multiple demands for water use, combined with a decrease in the available water reserves, as well as the degradation of water resources due to excessive use and pollution as a negative effect of human activity, impose a need for the rational management of human water use.

Modern societies are becoming aware that there is a need to change the existing development models towards the direction of sustainability. Hence, the collection and storing of rainwater, the recycling and reusing of water post-consumption, as well as other less conventional methods that are used for the creation of water reserves or the replenishment of already existing ones in various regions around the globe, are all management practices that are changing the status quo.

On the other hand, cities that have succeed in maintaining green areas as a component of the urban space, are now highlighting the need for the design and development of practices for the integrated management of the urban green, with methods that contribute to the sustainable management of the urban environment.