where can i submit my idea about a web community or networking site?

I have an idea for a website which is an online community with various sub communities and discussion groups etc. Also it will be a huge community and members from several fields.

But where can i submit my idea. I can't do crowdfunding since it is a fairly large project and its just me alone. Is there any web innovation contests or a place where i can share my idea so that it gets noticed?

PS: I can't do the development myself since its really challenging. Also i have the complete idea with all the necessary plans and execution methods. But need support.