Blue Green Dream

According to the eleventh principle of permaculture edges and borders are the most important parts of any ecosystem, since at the edge, you can find three distinct living spaces: the one inside the edge, the one over the edge, and the mixture of both in the vicinity of the edge, often hosting a plethora of lifeforms evolved specially for the unique conditions of the overlapping areas. 

This is why riverside forests, estuaries, or borders of meadows and woods are such important living spaces.

Natural waters flowing through cities are often times no more than giant waste sewages nowadays, with citydwellers completely torn apart from the river which a few centuries, or even decades ago was the main source of life, mean of travel, key of commerce for them.

Budapest is the prime example of what industrialized and centralized city "development" is doing to a once majestic river, and in the current century we see the activization of civil groups to mitigate the damage done and bring the people closer to their rivers (one of the best known NGO's are Valyo, affiliated to  the Mindspace project)

Blue Green Dream is an international project for exactly that purpose. Many woes of modern cities (like summertime overheating, extreme energy consumption for temperature control, noise) could be eliminated or mitigated by "blue-green" projects, smart solutions using plant coverage, rainwater capturing, green roofs and other ideas involving plant life and natural waters. If interested, you can check out the article about Blue Green Dream, here.