une structure de communication locale/depuis la base/citoyenne

English term (edited): "grass-roots"

I'm not sure that 'grass roots' was a terribly well chosen expression here in EN.

Usually, it means the 'base' — often in term of the 'rank-and-file' (members of a party, etc.). It's not entirely clear from the context exactly what the situation is here, so this might be a communication structure that connects to the lowest echelons of 'workers in the filed / at the sharp end', etc., or whether the sense is less of people and more of geography.

Either way, I think this solution in FR might work — mr maybe just use 'terrain' on its own, to be slicker?

The delegation noted that project funding should
[...] be based on needs assessments and should involve grassroots organizations, which would ensure that project activities were [...] able to adapt to existing structures. unesdoc.unesco.org
La délégation a observé que le financement des projets devrait être basé
[...] sur l'évaluation des besoins et impliquer des organisations au niveau local, garantissant ainsi que les activités des projets [...] pourront s'adapter aux structures

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