There is already the possibility to create environmental protection non-profits for a specific area. In France, and other countries, it gives you the right to participate in lawsuit and even collect reparation for ecological prejudice (https://www.euractiv.com/section/climate-environment/news/er.... You can't however sue on behalf of the river's endangered interests. Giving legal personnality doesn't necessarily change the law as the article implies but change the way the law works.
Our concept was to add 'economic personnality'. Natural resources such as a river would have a cryptoasset account collectively managed by donors. "Gardeners" are local people hired by this collective to execute maintenance tasks, or lawsuits, while this board of donors oversee the management of the founds. Compared to a local non-profit, you gain easy internationalisation of donors and more transparency on funds allocation, potentially avoiding corruption.
The key is in the governance rules. As pointed in the article, it is extremely difficult to represent fairly and combine populations' interests and environment protection at the local, national and worldwide levels.
A visual demo can be seen here http://forest.lesusineslouise.com/