"Het Grote Kanaal van Catan" (Catan's Great Canal) is a separately sold expansion to Catan.
A large area of Catan is threatened by drought. The only way out is to dig an enormous canal from the sea to this area. All knights of Catan are summoned to get this job done. Attracted by large financial gains, they start working on the canal. Mostly together with other knights, the knights complete bit by bit of the canal. Finally the fields of Catan can be irrigated and Catan has wheat again.