Resources South of the 'Hood

Received this from a reader and neighbor: Hello.  I am opening a cafe on Washington between Pacific & Dean avenues.  Although technically in Prospect Heights I live in Clinton Hill and look forward to reaching this community as well.

I am also trying to contact some block associations in the area but am having trouble finding any contact information.  Could anyone help me with this?  I am trying to find contact information for the Wa-Greene Association, the Prospect heights heibghborhood Development Council and the Atlantic Avenue Betterment Assocation.

Please leave your tips for Sarah in the comment section.  This isn't too far from us, so I suspect it could be a good hangout for neighbors in the soutn end of CH!