The Afgedamde Maas (Dutch pronunciation: [ˌɑfxədɑmdə ˈmaːs]; Dammed-up Meuse) is a former distributary of the Maas River (French: Meuse) in the Dutch provinces of North Brabant and Gelderland.

The former main branch eventually silted up and is today called the Oude Maasje.

With the completion of the Wilhelminasluis (nl) in 1896, the connection between the Maas and Rhine was closed.

The resulting separation of the rivers Rhine and Maas reduced the risk of flooding and is considered to be the greatest achievement in Dutch hydraulic engineering before the completion of the Zuiderzee Works and Delta Works.

[3] Floods of the waterway in 1993 and 1995, however, created the need to be able to close the Heusden Canal off from the Bergse Maas and maintain a fixed water level, and the Kromme Nolkering (nl) control lock was completed in 2002.