Min's mention of this being a Dutch film finally tipped me off. This is the 1972 film called "The Little Ark":

http://us.imdb.com/title/tt0068864/

The story is about two children, a Dutch boy and a Japanese girl, who are orphaned during the big flood in Holland in the early 1950s.

Just a few years ago you could find the VHS in the bargin bin at Walmart or on Ebay for a few bucks...now the tape appears to be out of print. The book the film is based on is readily available.

I vaguely remembered the film as I watched it, but I couldn't tell you where it aired on television in the '70s. It definitely wasn't part of the Festival, though it would have fit right in.

Well, it is available at Amazon, albeit for $65!