Heere Gracht

http://watercourses.typepad.com/watercourses/broad-street-canalheere-g.html

http://watercourses.typepad.com/watercourses/2008/09/broad-street-canalheere-graft-manhattan-sewer.html

I also found an old book on google that talks about the heere gracht, also known as the broad street canal:
http://books.google.com/books?id=aLULAAAAYAAJ&pg=PA106&lpg=PA106&dq=heere+graft&source=bl&ots=DKQl_qZI2E&sig=AiKRiiphswXVKYtRhdiBz0CmqfU&hl=en&ei=GRpITbzZIYjqgQf266GkBg&sa=X&oi=book_result&ct=result&resnum=5&ved=0CC8Q6AEwBA#v=onepage&q=heere%20graft&f=false


The large street sloping southwest to the East River shows the site of the canal.