Sudbury Valley Trustees
- Information about volunteer group committed to protecting wildlife habitat and ecological integrity of the Sudbury, Assabet, and Concord Rivers.
- http://www.sudburyvalleytrustees.org/

Lake Quinsigamond Watershed Association
- Community organization committed to restoring and preserving the Lake Quinsigamond watershed. Mission statement, historical photos, membership information, and event listings.
- http://www.lqwa.org/