Hallo Joanna

Participation in my country has a low voice . It is related to whom they pay for the project 

In The Netherlands spatial planning is very refined. All new and existing plans can be found on the websites of the responsible local authorities. Comments on new plans, or objections,  can be made by e-mail, and often in person on special meetings.

I hope this covers your question?

Evert.

In Croatia it is not possible to participate in spatial planning via Internet . The whole process is still analog and costly. 

Regards

Višnja Kukoč

One way would be to use crowdsourcing for feature truthing. By this I mean, that people can verify features on land against it's said position and attributes on the web map.

Google is currently doing on this with Google maps. Users are asked to verify some claims or attributes of places on the map once they visit the place in real life.